(REVISED MAINTENANCE MANUAL FOR WAGONS 2.

0)

CHAPTER – 9

TANK WAGON
THIS PAGE IS INTENTIONALLY LEFT BLANK
 CHAPTER-9 TANK WAGON 1

CHAPTER 9

TANK WAGON

Tank wagons form a special class of non-pooled rolling stock. They are classified
according to the product carried by the tank and its design. Tank wagons fall in the
following categories:

▪ Tanks as pressure vessels.

▪ Tanks for corrosive liquids.

▪ Tanks for petrol and other highly inflammable products.

▪ Tanks for middle distillates of petroleum and others products.

For information about these wagons in respect of their mechanical code and theproducts
carried, refer to Appendix “B” of IRCA Part III (Latest edition).

Since the population of four-wheeler tank wagons and tank wagons on UIC bogies have
been phased out, details of these stocks have not been included in this manual. If
required, 2001 version of WMM may be referred.

901. CONSTRUCTIONAL DETAILS

A. Underframe

The design of the underframe of four wheeled and eight wheeled wagon is generally
similar to that of other IRS wagons except that a pair of saddles is provided on the
underframe at each end for mounting the barrel. Refer to Chapter 5 for repair and
maintenance of underframe.

B. Barrel and saddles

The barrel is cylindrical vessel generally fabricated out of low carbon structural steel to
IS:2062 Fe 410CuW. Material specifications for various types of tanks are given in Table-
9.1. The barrel is placed longitudinally on the underframe and secured by means of
rivets/welding to the saddle. The saddle is welded on underframe at each end.
 CHAPTER-9 TANK WAGON 2

TABLE 9.1

MATERIAL SPECIFICATION
SN. Type of wagon Cylindrical portion Dished ends
Steel.toBS:1501- Steel to BS:1501-224-
Ammonia tank wagon type
01 224Gr.32ALT 50 or Gr.32 A LT 50 or
BTALN, BTALNM
ASTM-516Gr-70 ASTM-516 Gr.-70
Liquified petroleum gas tank Steel to BS: 1501-224- Steel to BS: 1501-224-
02 wagon type Gr32 A LT 30 or Gr32 A LT 30 or
BTPGLN ASTM-516 Gr. 70 ASTM-516 Gr. 70
Petrol tank wagons type
03 IS:2062 Fe410Cu-WA IS:5986 Fe360 Cu
BTPN
04 Heavy oil tank wagon BTOH IS:2062 E250CU IS:5986Fe360cu
Petrol tank wagon type
05 IS:8500 Fe 570B IS:8500Fe570B
BTFLN
Caustic soda tank wagon type
06 IS:2062 Fe-410CuWA IS:5986 Fe-360 Cu
BTCS
Tank wagon for phosphoric
07 ASTM A 240 55 316 L ASTM A 240 55 316 L
acid type BTPH

C. Barrel mountings and safety Fittings

Various types of barrel mountings are necessary for filling, measuring and decanting
depending upon the product handled. Safety fittings are generally provided inside the
dome on a diaphragm plate so as to protect them from accidental injury. These fittings
as used on various types of wagons are given in Table 9.2.
TABLE 9.2
DETAILS OF SAFETY FITTINGS
S. N Descriptio n of Particulars and Anhydr-ous Liquified Caustic BTPN/
fittings Mech. Code liquid petroleum soda BTFLN
Ammonia gas BTPGL/ BTCS
BTAL/BTAL BTPGLN
N/BT ALNM
1. Safety valves Nos. One Two One One
Drg. NO MIDLAND A- MIDLAND MIDLAN WA/
3200 A-3225 DA- TF-87
1739
Location Inside dome Inside Inside Outside
dome dome dome
Vapour tight at 22.15 15.85 2.46 01.4
pressure Kg/cm2 kg/cm2 kg/cm2 kg/cm2 Kg/cm2
Start of discharge Above 22.15 Above Above Above
pressure kg/cm2 15.85 2.46 1.4
kg/cm2 Kg/cm2
Drg. No.
Location
Disc not to
rupture pressure
kg/sq.cm N/A N/A N/A N/A
Rupture pressure
for disc
kg/sq.cm
 CHAPTER-9 TANK WAGON 3

D. Safety valve
The safety valve is provided to prevent building up of excess pressure inside the
barrel. Its fitting on the barrel is either on the diaphragm plate inside the dome
or on a separate opening on the barrel. Table 9.2 shows the location, number of
safety valves used and their working pressure, etc. for various types of wagons.
E. Relief valve
It is a spring loaded valve fitted on the barrel of tanks for corrosive liquids. Its main
function is to release built up pressure, if it exceed the working pressure limit.
Table 9.2 shows the type of wagons on which these are fitted and their working
pressure limit.
F. Safety vent
This consists of a frangible disc (lead or any approved material not affected by
lading) which ruptures at specified pressure. It is an additional safety fitting to
safeguard against the failure of the relief valve. When the built up pressure
exceeds the working pressure of the relief valve and the latter fails to function for
any reason the frangible disc of this safety vent ruptures to release the pressure.
G. Compressed air valve
It is provided on tank wagons from which the contents are unloaded by
compressed air. Its main function is to control the rate of discharge by controlling
the rate of air admission.
H. Vapour extractor cock
Its function is to extract vapour from the tank while filling (Drg. No. WA/TF-2116
& WD-86081-S/60).
I. Master valve assembly
It is a gravity discharge valve fitted with a hand wheel in the dome for manual operation.
J. In eight-wheeler stock, two bottom discharge valves are fitted, one on either
side and connected with the master valve through a tee pipe. The main function
of the valve is to control the flow of the contents and also to serve as an additional
safety stop in case the master valve fails or breaks. The bottom discharge valve
openings are also provided with blank flanges to be used with 2mm compressed
asbestos fiber jointing material to IS:2712-65 to serve as a further check on
accidental leakage of contents.
902. PERIODICITY OF OVERHAULING OF TANK WAGON
The periodical overhauling of IRS tank wagons should be carried out in fully
equipped mechanical workshops. The periodicity of POH is given below in Table
9.3.
TABLE 9.3
PERIODICITY OF
OVERHAULING

SN Type of wagon For 1st For subsequent

POH POH

01 Tanks for petroleum gas BTAL/BTALN/BTPH 4 ½ years 4 ½ years

Tanks for petroleum gas BTPGL, BTPGLN
02 4 years 4 years
 CHAPTER-9 TANK WAGON 4

03 BTPN 6 years 6 years

04 BTCS 4 Years 4 Years

A. INTERIOR EXAMINATION OF TANK BARREL

No person should be allowed to enter the tank barrel for internal examination/repair
unless the barrel is free from Toxic or inflammable fumes. Therefore, before internal
inspection of barrel is allowed, it must be steam cleaned/washed with solution of sodium
phosphate commercial or soda ash, washed with water or other suitable cleaning agent
as prescribed in case of various types of tank barrels.
B. STEAM CLEANING OF TANK BARRELS
The tank(s) requiring steam cleaning should be placed as near the steam supply line as
possible and protected against any movement. The berthing siding should be completely
isolated from all other traffic.
Tanks as pressure vessels, tanks for petroleum, other highly inflammable products,
vegetable oils, bitumen, coal tar and molasses are cleaned by steam. In case of pressure
vessels, it should be ensured that all the gas has been discharged to the atmosphere.
After ensuring that the tank barrel is no longer under pressure, the following sequence
should be followed:
1. In case of 4-wheeler tanks, remove the manhole cover together with manhole
housing, valves etc. and leave the tank exposed to atmosphere for few hours. This
clause is not applicable for BTPN.
2. Entry of staff in the tank barrel should be strictly prohibited and signs with suitable
legends displayed at a reasonable distance away from the tank(s) to be steam
cleaned.
3. Insert pipe through man hole and steam interior of barrel for 12 hours. In order that
the tank barrel is thoroughly steamed from inside, the stem pipe should be provided
with a “T” connection at its lower end and so directed as to blow steam towards both
ends.
4. Remove condensed steam collected in the tank barrel and keep the barrel exposed
to atmosphere for few hours.
5. Ascertain if the tank barrel is free from gas fumes. This may be done as follows:
(a) AMMONIA TANK BARREL
Fill the tank barrel with water and take a specimen of the same in a clean glass bottle
since ammonia is readily soluble in water. The specimen of water should be tested for
any traces of ammonia with red litmus paper. Any trace of ammonia in water would turn
red litmus blue. Another very sensitive method known as Nessler's test may be applied
to find out if the specimen of water contains any traces of ammonia. In this test, the
reagent used is a solution of potassium mercuric iodide with potassium hydroxide. This
reagent gives a brown colour when mixed with the specimen of water containing even
a minute trace of ammonia.
If ammonia is detected, empty out the tank barrel and refill with fresh water. This process
may be repeated till the tank barrel is free from ammonia traces completely.

(b) CHLORINE TANK WAGONS

Fill the tank barrel with water and take a specimen of the same in a clean glass bottle.
Since chlorine is readily soluble in water, specimen of water taken out should be tested
 CHAPTER-9 TANK WAGON 5
for any traces of chlorine. Any trace of chlorine in water would have a bleaching effect
on coloured litmus paper. If chlorine is present, the tank should be repeatedly emptied
and refilled wit h fresh water till free from chlorine traces completely.
(c) LPG TANK WAGONS
A clean bottle filled with fresh water is lowered through the manhole. A string is attached
to the bottom of the bottle before lowering. Tilt the bottle at the bottom of the tank to
allow its water to flow out and the gas in the tank to take its place. The bottle should be
left in this position for about 5 minutes and then withdrawn away from the tank. A lighted
match stick should then be brought near the mouth of the bottle or applied to the air or
gas inside and bottle. If there is no flame the tank is free from injurious gas. But, in case
it gives out a flame, the tank should again be steam cleaned.
After ascertaining that there is no trace of gas in the barrel the tank should be dried out
by blowing in hot compressed air before proceeding with inspection and repairs.
Alternatively, Gas should be checked with explosion meter.
903. CLEANING OF TANKS FOR CORROSIVE LIQUIDS
Caustic soda tanks: These barrels should be washed free of alkalinity with hot water.
Freedom from alkalinity can be easily ascertained by litmus test (if red litmus changes
to blue, there are still traces of alkalinity). After it is free from alkalinity, water should be
drained and barrel dried out before inspection and repairs.
904. INSPECTION OF TANK BARRELS
Generally, tank barrel defects will be indicated by hydraulic test but it is necessary to
inspect the barrel before hydraulic test so as to avoid accidental rupture of corroded
barrel plates at the time of hydraulic test. The barrel should be examined by a competent
inspector nominated by the CME, who must examine the interior of the barrel and the
internal fittings for their general condition and freedom from wasting, wear, tear and
damage. Measure barrel thickness by D-meter to ensure extent of corrosion. If the
examination indicates that the corrosion/erosion has taken place to such an extent that
the barrel is likely to rupture during hydraulic test, first carry out the repairs and then
give a hydraulic test.

905. TESTING OF BARREL

A. Ensure that all filling lines with low pressure and other apparatuses, which should not
be subjected to the test pressure, are disconnected.
B. The tank barrel and manhole orifice should then be completely filled with water at a
temperature which must not exceed 38 Deg.C (100 Deg.F) during test. The barrel
should be vented to prevent formation of air pockets while it is being filled. Before
applying pressure, the equipment should be inspected to see that it is tight. The tank
barrel should be tested by using a power driven hydraulic pump which should enable
a steady increase of pressure in the tank barrel. Test pressure should be maintained
for a sufficient length of time to permit a thorough examination of the barrel for any
leaks.
For the purpose of this test, connection is to be made through a dummy flange with
pressure gauge attached, fitted on the safety valve seating. The filling, discharge
and gas valve should be tested in position on the tank in following two ways:
a) With valves closed and outlet cap off, and
b) With valves open and outlet cap in position.
 CHAPTER-9 TANK WAGON 6

C. In case of any sign of leakage that may be evident from the drop in pressure under
hydraulic test, the pressure should be reduced by 20%. The lagging and insulation
is removed for locating leaks. The welded seams of the tank barrel should be given
a thorough hammer test by striking the plates on both sides adjacent to the weld.
The plate should be struck at intervals of about 6" for the whole length of all main
welded seams.
D. The hammer used for the above test should be of a material softer than the barrel
plate and its edges so rounded as to prevent denting of the barrel plates. The weight
of the hammer should not exceed 5 Kg.
E. The pressure should then be raised to the full test pressure and maintained for a
sufficient length of time, but not less than 30 minutes. Inspect all seams and
connection.
F. The tank barrel should remain secured to the underframe during this test.
906. BARREL TEST PRESSURE
The testing pressures for different types of wagons are given in the following table:

Description Mech. Code Hydraulic test pressure

Ammonia tank BTAL, BTALN 33.25 Kg/ cm2

LPG tank BTPGL, BTPGLN 22.1 Kg/ cm2

907. TESTING OF TANKS USED FOR CORROSIVE LIQUIDS

The procedure for testing of caustic soda tanks is the same as that given for tanks as
pressure vessels above except that their testing pressure would be 4.5 Kg/cm2.
908. TESTING OF TANK WAGONS USED FOR PETROL AND MIDDLE
DISTILLATES OF PETROLEUM AND VEGETABLE OIL
The following procedure should be followed for hydraulic test of petrol tanks:
A) Remove the safety valve from its seating and fill the tank completely with water.
Provide connections with the hydraulic pump through the safety valve opening.
Close the manhole cover and fully tighten it. It should be ensured that the bottom
discharge valve is properly closed before filling the barrel with water. The pressure
should be increased gradually by means of a hydraulic pump provided with a
pressure gauge. Close the control cock as soon as the hydraulic pressure reaches
2.8 Kg/ cm2 for BTPN wagons. Watch the pressure for a minimum period of 30
minutes.
B) In case of leakage (which will be evident from the drop in pressure under hydraulic
test), the joints should be checked first and made tight. Thereafter, the well seems
of the tank barrel should be examined thoroughly by applying soap solution, which
will show up the crack or other source of leakage.
909. REPAIRS TO TANK BARRELS BY WELDING
A. Pressure vessels
Pressure vessels requiring repairs should be inspected by a competent authority
approved by Chief Controller of Explosives. A workshop undertaking such repairs must
be properly equipped for the same and facilities for radiographic examination of the
repaired joints must be available. The detailed procedure for repairs of pressure vessels
is given in Appendix – IV.
 CHAPTER-9 TANK WAGON 7
B. Tanks for transport of corrosive liquids
i. Tanks used for transport of corrosive liquids suffer most, commonly from pitting and
also have a tendency to develop cracks. Pits when not deep enough to affect the
strength of the parent plate may be chipped to sound metal welded and then ground
flush to the original thickness of the plate. When pits are in a close group or in one straight
line and are deep enough to affect the strength of the plate, the affected area should be cut
out and replaced with a let in patch.
ii. Cracks should be fully explored to ascertain their extent. The crack may be on
surface or in full depth of the thickness. If possible, a portable magnetic crack
detector should be used. Such detector are manufactured in the country and are a
very useful piece of equipment for every railway workshop. In absence of crack
detector, dye penetration test shall be performed to ascertain extent of crack. A
12mm dia hole should be drilled at the ends of the crack and the full length of the
crack should then be carefully chipped and C grooved for welding. Removal of all
paint, grease, oil, dirt etc. by frame heating and brushing is essential both for the
purpose of proper inspection and to prevent contamination of the welded joint.
Perform DP test and then do welding.
iii. After completion of welding from one side, the other side of the crack should be
grooved, cleaned and welded. It is preferable if the welding is done from the inside
of the barrel and is in the down hand/horizontal position. Flush ground the welded
position and perform DP test along the weld.
iv. If a crack occurs in an area where the plate is wasted and of inadequate strength,
the defective portion should be cut out and replaced with a let in patch. It must be
ensured that the let in patch is of the same material and thickness as the parent metal.
Corners of patches should be rounded to a minimum radius of 25mm and edges must
be carefully prepared to obtain a V butt weld. Weld deposits should be smoothened
flush with the parent metal. Perform DP test and radiography of barrel plate.
C. Tanks for petrol, middle distillates of petroleum, vegetable oil etc.
The repair procedure will generally be same as described above.
D. Welding procedure and technique
i. Only approved brands and grades of electrodes should be used. Lists of such
approved brands and grades are published by RDSO every year and these should
be available in all workshops and repair depots for reference and guidance.
ii. Welding should be as possible done in the down hand position. Welding current (also
polarity if direct current is used) should be set as recommended by the electrode
manufacturer.
iii. Transverse speed of the electrodes should be controlled to obtain proper fusion of
the parent metal.
iv. After every interruption of the arc, welding should be restarted ahead of the previous
deposit and then moved back to fill the crater before proceeding forward again.
v. Care should be taken to remove slag before depositing successive beads.
 CHAPTER-9 TANK WAGON 8

E. Welding of stiffening plate.

Weld reinforcement should be made flush with the parent metal of the tank barrel for
welding a stiffening plate.
First, tack weld the stiffening plate in the position as below. Stiffening plate to be fitted
from out side only. They should be welded with the angle in the case of old design
wagons having the bearing plate inside. In case of new designs having both angle and
bearing plate outside, weld with the existing bearing plate. The welding should be
completed as shown in Fig. 9.1.
 CHAPTER-9 TANK WAGON 9

910. REPAIRS AND TESTING OF TANK BARREL MOUNTING FITTINGS.

A. FITTINGS OF PRESSURE VESSELS
a) Safety valve
The safety valve should be given a pneumatic test. It must be vapourtight against leakage
at pressures indicated in Table 9.2.
The safety valve adjustment should not be interfered with unless repairs to the valve
become necessary or the valve operates incorrectly. In such cases, it must be repaired,
correctly adjusted and re-tested at the pressure specified.
b) Packing and seals must be particularly checked for leaks, and those found defective
or damaged, perished, should be changed. The packing should be of correct material
and size/shape.
Since deteriorated seals and dirt on the seals are the most frequent cause of leakage, the
seals should be given careful attention. Changing of resilient seals of liquified petroleum
gas tank wagons, when the vessel is under pressure within 10 pounds of the operating
pressure of the valves, should not be attempted.
c) Other fittings of pressure vessels:
i. Apart from the safety valve, each type of mounted pressure vessel has its own
special fittings. The fittings are specific for each type of vessel and details regarding
their examination andmaintenance are contained in instructions pamphlets published
by the RDSO for the respective wagons.
ii. Items to be particularly checked for defective, damaged or perished packing. “O”
ring, “V” ring and lead seals. Asbestos packing or rubber packing is commonly used
depending uponthe type of vessels and commodity carried. V rings are pressureseals,
which expand on application of pressure to remain leak proof.
iii. The various valves and fittings of these vessels are usually designed to give long
periods of trouble free service and should not ordinarily require any maintenance
other than cleaning. However, if a fitting become defective, it would be desirable to
consult the manufacturer. Most of these valves and fittings are specialized pieces of
equipment, made of special materials. Substitution by components made of incorrect
materials or to wrong tolerances could have undesirable repercussions.
iv. The main fittings are two liquid education valves, a vapour education valve, a safety
valve, a slip tube for determining liquid level, a pressure gauge, a thermometer well
and excess flow valves which control the rate of flow through the three education
valves.
B. PRESSURE GAUGE
In view of the possibility of pilferage/damage, the pressure gauge should be fitted only
when required at the time of filling or discharging, or when the pressure is to be checked
enroute. It should be removed before releasing the tank wagon. The necessary valve
and fittings for attachment of the pressure gauge are provided on the manhole cover
plate.
911. FITTINGS OF TANKS FOR CORROSIVE LIQUIDS

A) Pressure relief valve/safety valve: These valves should be given a

pneumatic test at the pressures indicated in the table 9.2.
B) Safety vent with frangible disc: The safety vent should be provided with rubber lining
and closed with a frangible disc which should rupture at a pressure not exceeding
the predetermined value. The ruptured frangible disc indicates that excessive
 CHAPTER-9 TANK WAGON 10
pressures have been built up in the tank wagon and may be the first sign of
malfunctioning of the safety valve. The cause needs to be investigated and removed.
A ruptured frangible disc should be replaced by a new frangible disc, conforming to
the required specification.
C) Globe valves/compressed air valves/washout valves: All these valves should be
tested on a bench by applying hydraulic pressure by means of a pump and it should
be ensured that they are leak proof at the pressures of individual wagons mentioned
under “Testing of the Barrel” in para 1008 above. Leaky valves should be attended
for defects before fitting body on the tank.

912. FITTINGS ON TANK WAGONS OF PETROL, OTHER INFLAMMABLE

PRODUCTS, VEGETABLE OIL ETC.

A) Safety valve: These valves are provided on petrol tank wagons. The safety valves
should be subjected to pneumatic test after repairs/POH at the pressure given.
B) Master valve: Wherever repairs to the master valve and its seating are undertaken,
after filling the valve should be tested in position under air pressure of 0.35 to 0.56
Kg/ cm2 (5 to 8 psi), the tank barrel being filledwith water to a minimum height of 150
cms. The hydraulic test should be carried out keeping the bottom discharge valve
and blank flange open.
C) Bottom discharge valve: The bottom charge valve should also be tested in position
under air pressure of 0.35 to 0.56 Kg/ cm2 (5 to 8 psi) after filling the tank barrel with
water to a minimum height of 150 cm. Master valve should remain open during this
test. This test to be done after satisfactory testing of the master valve.
D) Blank flange: The blank flange should be tested in the same manner as the master
valve and bottom discharge valve after ensuring that a gasket of specified material
has been fitted underneath.
913. TEST REPORTS AND RECORDS OF INSPECTION
Re-tests of all tanks, safety valves and rubber lining must be certified by the official
making the tests and records maintained in the office of the CME. Certification must
show railway initial, number of tank wagon, pressure to which tested, date and place of
test, etc. A copy of the certificate may be submitted to the party owning the tank wagon
in the case of private or dual owned tank wagons.

The testing authority must maintain detailed records of the tests carried out on each
individual tank wagon.

A special report must be submitted to the CME concerned in every case where the
maximum permissible working pressure is reduced or the examination shows that the
tank cannot continue to be used with safety unless certain repairs are carried out
immediately or within a specified time. Such a tank wagon must not be commissioned
in service till it is certified fit for use after repairs and re-testing under specified pressure
by the testing authority.

The testing authority competent to test the barrel, safety valve and rubber lining under
the above clause is to be nominated by the CME.
914. IMPORTANT MODIFICATIONS
The important modifications to be carried out in workshops and depots are given in
Table 9.4.
 CHAPTER-9 TANK WAGON 11
915. PAINTING AND LETTERING
Full schedule of painting and lettering following as per marking diagrams issued by RDSO
for each such type of wagon. The test particulars must be marked at the prescribed
places on the tank wagon. In case of tanks used for acids the external surface of the
tank barrels should be printed with an acid-resistant paint to prevent external corrosion.

Specification of the paint should be generally as per G-72/Marking diagram. While using
these paints care should be taken to prepare the surface properly so that all rust loosely
adherent scale and dirt are removed by means of metal scraper suitable hammer and
wire brush. Grease oil etc if present should also be removed with white spirit or other
suitable solvent. In case of tanks already used for carrying acid care should be taken to
wash down the surface with water to remove all traces of acid and to ensure that the
surface in dry before application of paint.
TABLE 9.4
LIST OF IMPORTANT MODIFICATIONS IN BTPN TANK WAGON

TO BE DONE IN
ITEM RDSO’s
SN Purpose Drg. No. SICK NEW
DESCRIPTION REF. ROH POH
LINE BUILT
1. Sealing Gasket ring inTo remove the
WD-86081- MW/BTPN
the main hole & filling problem of sealing
S/ 60 & WD- dtd. Yes Yes Yes Yes
pipe cover ring comes out
86081 -S/ 61 13/16.06.03
from the groove
2. Pin for Master valve Length of the pin
MW/BTPN
spindle & valve increased to avoid WD-86081-
dtd. No Yes Yes Yes
operating screw the breakage of S/ 65
pin 10.10.03
3. Valve spindle nut Material valve
bottom spindle nut bottom
changed from IS:
MW/BTPN
1458 (bronze) to WD-86081-
dtd. No Yes Yes Yes
stainless steel IS: S/ 66
10/14.10.03
660307r18Ni9 to
avoid the nut get
sheared off
4. Flanges cover design Thickness of cover
of bottom discharge plate reduced to
MW/BTPN
pipe 3.15 mm from 8.0 WD-86081-
Dt. Yes Yes Yes Yes
mm & embossed S/ 65
9/14.12.03
at the centre for
stiffness.
5. Filling pipe A magnet at the
bottom of filling
pipe provided to
arrest the foreign
MW/BTPN
item such as nut, WD-86081-
Dt. 29/12 No Yes Yes Yes
bolt & locking wire S/ 61
/6.01 2004.
etc. to avoid the
damage of the
seat of master
valve
6. Provision of rubber To avoid the
piece on the barrel damage of dome WD-86081- MW/BTPN
Yes Yes Yes Yes
cover during S/ 58 Dt. 22.02.05
opening of cover.
 CHAPTER-9 TANK WAGON 12
7. Stiffener plate Additional stiffener
plates provided on
WD-86081-
the top of centre
S/ 53 MW/BTPN
sill and above the
& Dt. Yes Yes Yes Yes
back portion of
WD-86081- 14/15.7.05
CBC to avoid the
S/ 54
lifting of CBC and
hitting of barrel.
8. Manhole joining Location of holes
on the right side
portion of manhole WD-86081- MW/BTPN
No. Yes Yes Yes
joining changed as S/ 61 Dt. 02.04.04
correctlysuggested
by S. Rly.
9. Bolster bottom flange Bolster bottom
flange profile WD-86081-
modified and S/ 53,
stiffener added to WD-86081- MW/BTPN
remove the S/ 55 dtd No. Yes Yes Yes
possibility of centre & 07.07. 09
sill crack as WD-86081-
reported by JHS S/ 66
Workshop
10 Bogie mounted brake To develop the New
system new braking Drawing No.
system with better WD-09050-
performance and S/00
lesser rigging parts to 11
(Twelve
Drgs.) No. No. No. Yes
prepared for
BMBS, other
drawings will
be as per
WD- 09050-
S/00(Index).

916. EXAMINATION AND REPAIR OF TANK WAGONS BY C&W SUPERVISOR

AT SICK LINE & BASE DEPOT
A) Any repairs to tank barrels should be done only at nominated sick lines where
facilities for steam cleaning are available. After repairs, the barrels and valves must
be tested to ensure that there is no leak. Safety valves must not be permitted with
any nut or bolt deficient from sickline. The tank wagon discharge valves blank flange
and manhole covers should be secured with full complement of bolts and nuts
whenever the tank wagons are empty or taken out of sickline. Whenever tank wagons
containing petrol or other inflammable fluids are examined, only specified safety
torches (battery torches) should be used for this purpose.
B) Before any repairs are commenced on such stock, due precautions must be taken to
remove all such petroleum and other inflammable fluids as required under IRCA red
tariff and special instructions issued by the railway/railway board from time to time.
These precautions must be observed on empty tank wagons also and no staff should
be allowed to enter the tank or to bring naked light or matches near it till the tank
has been steam cleaned and tested free of vapour.
The following checks should be carried out by train examining staff before a tank wagon
is certified fit for loading:
a. Master valve : Leakage of master valve should be checked while keeping the
bottom discharged valve open.
 CHAPTER-9 TANK WAGON 13
b. Bottom discharge valve : Proper functioning and fluid tightness of the bottom
discharge valve should be ensured.
c. Blank flange : The blank flange of the correct thickness made out of steel plate and
with a gasket of proper material between the blank flange and bottom discharge
valve flange should be tightened by six bolts and nuts.
d. Tank barrel : Tanks with cracks on barrels should be marked sick.
e. Leaky tank barrels : The leakage of tank barrels may be caused dueto one or more
of the following reasons:
i. Mechanical injury to the valve face and/or valve seat as a result of foreign material,
particularly nuts and bolts finding their way inside the tank wagon.
ii. Valve seats not properly secured to the stool by proper interference fits.
iii. Mal functioning of master valve.
917. PRECAUTION WITH LEAKY TANK WAGONS
A. BTAL, BTALN tank wagons
Ammonia gases are poisonous gases and have a characteristic pungent odour, which
gives warning of their presence in the atmosphere before dangerous concentrations are
attained. In the case of ammonia, if sufficient concentration of the gas is present in the
atmosphere, it will irritate the eyes and the respiratory system. As such, in the event of
leakage, all present in the vicinity should be warned to keep on the wind ward side of the
leak.
B. BTPGL & BTPGLN tank wagon
Action in any particular case will depend upon existing conditions, and good judgement
will be necessary to avoid disastrous fires on one hand and useless sacrifice of valuable
property on the other hand:
a. When a tank wagon is leaking, all flames or fires near it should be extinguished or
removed. No smoking should be allowed. Spectators should be kept away. Only
battery-operated torches or incandescent electric lights with gas proof sockets
should be used.
b. Oil lanterns or signal lamps necessarily used for signaling must be kept far away and
at as high an elevation as can be obtained from the tank and on the side from which
wind is blowing. The vapour will go with the wind, not against it. The ash pans and
fire boxes of steam locomotiveare sources of danger especially when wind is blowing
across the leaking tank towards them. The locomotives be moved away from the
site and ash pit fires be extinguished with water.
c. The leaky tank wagon should be removed as quickly as possible to an open area
where the escaping gas will be less hazardous.
d. Earth should be spread over any surface on which the LPG has leaked out in liquid
form.
e. A leaky tank, which has been emptied, should under no circumstances be sent to
the loading point and should be suitably stenciled as such. A leaky tank wagon must
only be dealt with in a fully equipped mechanicalworkshop.
f. Recommended procedures to stop leaks in dome fittings:
i. The liquid outlet valves face each end of the tank wagon, while the vapour outlet
valves face the sides of the wagon. If there is leakage around the valve hold down
bolts, tighten the bolts until the leakage stops. If leakage persists, isolate the tank
wagon and notify the oil company concerned.
 CHAPTER-9 TANK WAGON 14
ii. If there is any indication of leakage around safety valve, which is in the centre of the
dome, it should first be checked whether the valve is merely performing its function,
i.e., relieving excess pressure. However, if considerable flow of gas is evident,
isolate the tank wagon and notify the oil company concerned.
iii. If there is leakage from the outlet of the valve, turn the valve handle by hand, if it does
not stop leaking, the seat is defective. Do not try to use a wrench but insert and tighten
the plug attached by a chain to the valve.
iv. If there is any leakage out of the thermometer well, the only thing that can be done is
to tighten the plug. If the leak cannot be stopped, by tightening, isolate the wagon
and notify the oil company. DO NOT TAKE THE PLUG OUT FOR LAPPING OF
THE THREAD. The thermometer well is, in fact, a part of the shell of the tank, and if
there is any evidence of leakage from the thermometer well, a bad situation is
indicated. If the plug is removed when leakage is present, liquid will probably be
discharged with a consequent extreme hazard.
v. A high percentage of any leaks that might occur will be in the gauging and sampling
devices. The sampling valve is a part of a fixed line to the bottom of the tank. The
valve on the gauging device (slip tube) must be used in gauging the volume of the liquid
in the tank wagon. It is open while moving the gauge down to find the liquid level. Once the
liquid level is found, the valve should be closed. In both cases, a turn of the shut off valve
handle will probably stop any leakage that might be occurring through the valve.However, on
the slip tube, which is moved up and down to determinethe liquid level, there is a packing
gland, which is subject to wear. If the leak is occurring through this packing gland, tighten
thepacking nut until the leak stops.
vi. The Junior Engineer (C&W) staff must be most careful that liquefied petroleum gas
does not get on their skin. The effect is substantially the same as when dry ice comes
in contact with the skin viz. freezing. The white fog of its discharge can distinguish
liquefied petroleum gas while liquid can only be distinguished by careful viewing. In
many cases, soapy water must be used to locate liquid leaks because they are not
readily visible.
C. All other types of tanks
No leaky tank wagon should be allowed in service and such tank wagons should be
attended in properly equipped sick line and/or shops.
D Additional precautions in cases of heavy leakage/spillage
▪ In case of heavy leakage which cannot be stopped by closing of valves, evaluate
leaks and determine repair materials and techniques to be used. Contact nearest
Rly. Station and oil installation.
▪ The station master shall send telegraphic/telephonic advice to nearest Train
Examiner & control and other authorities
▪ Ensure that there are no ignition sources including mobile phone nearby and passers
by do not smoke or carry open flame.
▪ Isolate the heavily leaky wagons and keep as far away from the train as possible.
▪ During isolation, take care to avoid any hammering, sparking.
▪ Have “Dangerous” “not be loose shunted” Labels affixed on both
▪ sides of such wagons.
▪ Carden off the area.
918. PRECAUTIONSTO BE TAKEN AT LOADING AND UNLOADING POINTS
(TANKS AS PRESSURE VESSELS)
 CHAPTER-9 TANK WAGON 15
i. Ensure that the tank is loaded/unloaded under supervision of a responsible and
competent person and all precautions taken by him to see that the persons engaged
in the filling/discharging operations are properly protected against the poisonous gas
contaminated atmosphere. A list of precautionary measures to be taken by the staff
must be exhibited at a conspicuous place near the installation. The
loading/unloading connections must be securely attached to the pipe line before
valves are opened.
ii. Ensure that the tank to be loaded/unloaded is placed in position, preferably under
shade, and secured properly against any movement. The handbrakes must be put on
and hand brake lever secured in that position.
iii. Shunting of any kind of the tank under loading/unloading must be strictly prohibited.
iv. Ensure that points leading to loading/unloading line on which the tank is to be
loaded/unloaded are set and pad locked so as to isolate the line on which
loading/unloading is to be done. If loading/unloading is to be done at one end of a
long siding, it must be protected properly by a scotch block or other authorized device
so as to prevent any wagon dashing against the tank wagon. It must also be ensured
that shunting is not permitted on the same line when loading/unloading is being done.
v. Ensure that signs are exhibited at a suitable distance away from the tanks on the
approach end or both ends as applicable.
vi. Ensure that the tank is filled by connections to the liquid valves, which have dip pipes
to the bottom of the tank. The other gas valve is connected to the absorption system
of the chlorine plant or Ammonia plant. In the case of LPG tanks, two liquid valves
are provided for loading/unloading of the tank. The rate of flow of LPG liquid becomes
too great in case only one liquid line is provided and this may result in the excess flow
valve (provided inside the pipes below the diaphragm plate) closing off. Use of only
one valve may result in closing down of excess flow valve repeatedly.
vii. The tank should not be loaded beyond its marked capacity under any circumstances.
viii. Tank wagon(s) must not be allowed to stand with loading/unloading connections
attached after loading/unloading is completed.
ix. Throughout the entire period of transfer operations or while the tanks connected to
loading/unloading devices, the tank(s) must be continuously attended to by the
operator.
x. If it is necessary to discontinue transfer operations for any reasons, all
loading/loading connections must be tightly closed and closure of all other concerned
components strictly ensured.
xi. On completion of filling operation, the valves should be properly closed and dome
cover sealed. The caution signs should then be removed and padlocks on the points
opened to enable the tank(s) to be taken out for attaching to trains.
xii. The loading of pressure gas tank wagons must be carried out by using a gas
compressor i.e., the compressor will be connected to the gas valve on the tank. The
liquid valve on the tank will be connected to the storage tank. By ensuring that the
pressure in the tank barrel is about 10 lbs/sq.in (gauge) above the pressure in the
storage tank, the liquid gas will discharge itself. To avoid reverse siphoning of the
liquid gas into the tank barrel, the above pressure must be maintained inside the
barrel till such time the whole contents are discharged.
xiii. While discharging, the pressure inside the tank barrel should be maintained steady
so as to avoid any chance of sudden evaporation and consequent chilling of the
barrel plates.
 CHAPTER-9 TANK WAGON 16
xiv.When all the liquid gas has been transferred, which will be indicated by the level
ceasing to rise in the storage tank, the liquid valve on the tank must be closed.
xv. All tools and implements used in connection with transfer operations must be kept free
from oil, grease, dirt and grit.
xvi.Seals and other substances must not be thrown into the tank. Care must also be
taken to avoid spilling of the contents over the tank.
919. LOADING AND UNLOADING CORROSIVE LIQUIDS
i. Only Phosphoric acid and caustic soda 8-wheeler wagon exist in Railways. Caustic
soda lye (liquor) having specific gravity of 1.51 at 150C or a concentration of not less
than 48% and containing not more than 3% of any chloride and no free chlorine, is
loaded in the caustic soda tanks.
ii. Before loading, it should be ensured that the tank barrel and washout valve is free from
any leaks and the dome cover fits airtight. A leaky tank wagon should not be allowed
to run on line and it should be suitably marked for repairs after unloading. Dome
fittings should be inspected for leaks and other defects before unloading to avoid acid
spillage or spraying.
iii. An air space of not less than 5% of the capacity of the tank should be left. When higher
concentrations are filled, it should be ensured that tank wagon is not overloaded
beyond its carrying capacity in tonnes.
iv. All empty tank wagons should be securely closed airtight as sulphuric acid is self-
diluting and absorb moisture from atmosphere. Dilute sulphuric acid is highly
corrosive to mild steel.
v. During the loading and unloading operations, caution signs must be exhibited at a
suitable distance away from the tank on the approaches at both ends.
vi. Smoking or bringing a naked flame or lamp near sulphuric acid wagons is strictly
prohibited. An incandescent electric light with gas proof socket should be used.
vii. At the time of loading/unloading, the tank wagons should be protected by means of
scotch blocks or other suitable devices to prevent any risk of damage due to
inadvertent shunting.
viii. Steel spanners/tools should not be used as they may cause sparks on striking,
Brass tools may be used.
ix. All spillage of acid should first be neutralized by means of hydrated lime and
washed down the drain with an adequate supply of water.
x. The tank wagon has a top discharge arrangement. For loading the tank, it should be
connected to an air compressor through the globe valve and it must be ensured that
the pressure in the tank does not rise above 30 psi. The discharge pipe should be
connected to the designated line after removal of the blank by means of a suitable
flange after inserting a rubber gasket/lead lining. The gasket/lead lining prevents
spillage of acid on the tank barrel.
xi. The filling in of the tank wagon is also affected through the discharge pipe by
connecting it to the consignee's acid supply pipeline by means of a suitable flange
after inserting a rubber gasket/lead lining. During the filling in operation, the globe
valve/air compression valve should be in open position to permit exit of air from the
tank.
 CHAPTER-9 TANK WAGON 17

920. LOADING AND UNLOADING OF TANK WAGONS

i. Adequate supervision of filling and emptying of wagons is necessary to ensure that
this is done in an authorized manner only.
ii. The filling should be done from the filling and discharge pipe. This pipe is provided
with a rubber lined flange. A corresponding flange should make the connection to
the acid supply line after inserting a rubber gasket between the filling flange and the
supply flange. The gasket prevents spillage of acid on the tank barrel and would also
prevent damage to the rubber lining on the filling/delivery flange.
iii. In order to give vent to the air inside the tank barrel, the air flange should be removed
for the filling operation.
iv. The decanting should be done after connecting the delivery pipe to the discharge
flange. Connecting with the help of a suitable flange using a rubber gasket should
do this.
v. The air pipe flange should be removed and a pneumatic line should be connected
to the air pipe, by means of a suitable flange after inserting a rubber gasket.
vi. The pneumatic pipeline should be connected to a pneumatic system wherein the
pressure in the line cannot exceed 1.75 Kg/cm2 (25 psi). This is done to prevent
damage to the tank barrel.
vii. After the tanks have been unloaded, they should be filled with clean water at a
temperature not exceeding 380 C (1000 F). This is done to prevent deterioration of
the rubber lining as the rubber decomposes in presence of air.
viii. All spillage of acid should be washed down the drain with an adequate supply of
water. If the spillage is excessive, the acid should first be neutralized by means of
hydrated lime.

921. PRECAUTIONS FOR TANKS FOR PETROLEUM AND OTHER INFLAMMABLE

PRODUCTS
A. At loading points
i. Ensure that all tank fittings are in good working condition.
ii. Ensure that tank fittings are provided with requisite anti- pilferage devices.
iii. Ensure that the safety valve is intact and properly sealed.
iv. Ensure that the master valve is fluid tight.
v. Ensure that the bottom discharge valve is fully closed and fitted with a blank flange
and gasket before commencement.
vi. Ensure that the vapour extractor cock and vent plug are open before
commencement of loading.
vii. Ensure that loading is done through the filling pipe only.
viii. Ensure that recommended air space as specified for the particular petroleum
product is provided and that payload does not exceed the permissible limit.
ix. Remember to close the vapour extractor cock after loading.
x. Remember to fit the cap on the vapour extractor cock after loading.
 CHAPTER-9 TANK WAGON 18
xi. Remember to fit the cap on the filling pipe after loading.
xii. Ensure closure of the vent plug cock after loading.
xiii. Provide proper sealing when dome cover eye bolt nuts are tightened.
xiv. Make sure that the dome cover is closed after loading.
B. At unloading points
i. Close the master valve after unloading.
ii. Close the bottom discharge valve after unloading.
iii. Fit the dummy flange with gasket and all its bolts back in position after unloading.
iv. Close the dome cover after unloading.
v. Tighten eye bolt nuts of dome cover after unloading.
vi. Do not allow rough, hump or loose shunting.
vii. Do not allow unauthorized persons to operate valves.
viii. Do not allow any person to enter the tank barrel for internal examination/repairs unless
the barrel has been steam cleaned.
ix. Do not undertake repair of the tank barrel by welding unless it is properly steam
cleaned.
x. Do not start welding repairs on a tank wagon fitted with roller bearings unless the
barrel is properly earth and roller bearings are short circuited.
xi. Do not allow tank wagon to move from loading/unloading points unless the tank fittings
are properly refitted and dome cover closed.
C. Action to be taken in case of fire:
• Eliminate source of ignition.
• Organize dispersal of vapour.
• Cut-off source of leakage to extinguish fire.
• Allow the fire to continue under controlled conditions, till all the fuel is burnt.
• Use water spray to cool equipment on fire and adjacent equipment.
• Not to extinguish flame at leak to avoid uncontrolled explosive re ignition.
• Inform all concerned depending upon gravity of fire.
• Contact LPG bottling plants for assistance in case of emergency
922. MAINTENANCE AND REPAIR IN SICK LINE
A) No person should be allowed to enter the tank barrel for internal examination/repair
unless the barrel is free from noxious or inflammable fumes. Therefore, before internal
inspection of barrel is allowed, it must be steam cleaned/washed with solution of sodium
phosphate commercial or soda ash and washed with water or other suitable cleaning
agent as prescribed in case of various types of tank barrels.

B) Before any repairs are commenced on such stock, due precautions must be taken to
remove all such petroleum and other inflammable fluids as required under IRCA red
tariff and special instructions issued by the Railway/Railway Board from time to time.
These precautions must be observed on empty tank wagons also and no staff should
be allowed to enter the tank or to bring naked light or matches near it till the tank has
 CHAPTER-9 TANK WAGON 19
been steam cleaned and tested free of vapour.

C) Any repairs to tank barrels should be done only at nominated sick lines where facilities
for steam cleaning are available. After repairs, the barrels and valves must be tested for
leak. Safety valves must not be permitted with any deficient nut or bolt from sickline.

D) The tank wagon discharge valves blank flange and manhole covers should be secured
with full complement of bolts and nuts when the tank wagons are released from sickline.

E) Whenever tank wagons containing petrol or other inflammable fluids are examined, only
specified safety torches (battery torches) must be used for this purpose.

F) In addition to routine attention to underframe, suspension, running gear, draw gear,

buffing gear and braking gear, the following examinations and repairs to be done in
sickline: -
i) Examination of tank barrels.
ii) Testing of discharge valves and barrels to ensure that there is no leak.
iii) Adjustment and examination of security fittings of safety valves
iv) Examination of tank barrel insulation where provided.
v) Examination of dome equipment
vi) Examination of barrel, cradles and fastening arrangements

G) The checks as mentioned in para 917 B must be carried out by train examining staff
before a tank wagon is certified fit for loading.
H) Testing of barrel is to be done as given in para 905.
I) Procedure for repairs of tank barrel to be followed as given in para 909.
J) The important modifications to be carried out in depots are given in Table 9.4.
K) The painting and lettering to be done as given in para 916.
923. MAINTENANCE AND REPAIR IN WORKSHOP DURING POH
The periodical overhauling of IRS tank wagons should be carried out in fully equipped
mechanical workshops. The periodicity of POH (refer IRCA Part III Rule 2.4.3) is given in
Table 9.3. For various type of tank wagons, detailed maintenance procedure is given is
RDSO publications listed in Table 9.5. The detailed procedure for repair of tank wagon
pressure vessels is also described in Appendix-IV.
924. Instruction for Maintenance and Operation of Bogie Petrol Tank Wagon Type
BTPN.
(Amendment No. 4 of July, 2012 applicable to RDSO technical Pamphlet No. G-90 of
November, 1991)
To prevent possible fire risks due to electrical tracking through OHE-

1. Oil companies/ loading parties shall switch over to non-metallic sealing wires for dome
covers progressively.

2. Till such time the switchover to non-metallic sealing wires does not materialize, the Oil
companies/ loading parties shall ensure that the metallic sealing wires are wound taut
and the loose/ uncut length of the sealing wires does not project more than 1inch (25
mm) vertically from the centre of the hole provided in eye bolts for sealing. Loose
winding of sealing wires all around the Dome Cover is strictly prohibited.
 CHAPTER-9 TANK WAGON 20

3. Used sealing wires shall be removed completely from the Dome Cover and shall not be
left on the wagon Body/ Barrel.

925. Prevention of fire risks due to proximity of sealing wires with

contact wire of OHE

1. Correction slip 7 of IRSOD 2004 espouses a minimum electrical clearance of 270 mm

of Rolling Stock from the contact wire.
2. Reports from zonal railways have been received as regards adhoc metallic sealing
arrangement being adopted by loading parties at loading points.
a) It is reported that long metallic wires are wound around various eyebolts (With holes for
sealing wires) of the dome cover, sometimes crossing the dome cover diagonally.
b) Similarly, it is also reported that at unloading points, the metallic lead seals are left
hanging at the dome cover after the unloading operation.
c) This leads to long uncut and undesirable lengths of metallic sealing wires hanging from
the dome covers, which during run, may breach the minimum electrical clearance
requirements IRSOD.
d) Some representative pictures are enclosed as appendix-I to this annexure.

3. The design of the eye bolts as per ISO drawing No. WD-86081-S-60 and WD- 86081-
S-61 is such that sealing in even one bolt is enough to ensure the theft protection as it
shall not be possible to open the dome cover without damaging the seal. At max, sealing
on two adjacent bolts, individually, shall suffice to ensure anti-theft protection.

4. The practice of winding the sealing wires all around the dome cover eye bolts, in a loose
condition, is not correct. Being a potential cause of fire due to electrical tracking, the
same should be discontinued.
5. While ensuring the sealing on one/ two adjacent bolts, it should be ensured that the
uncut length of the metallic sealing wire in vertically taut condition does not project
more than one inch from the centre of the hole provided in the eyebolt for sealing.
This shall ensure adequate electrical clearance from the OHE.
 CHAPTER-9 TANK WAGON 21
6. Similarly, at unloading points, the used sealing wires must be removed from the wagon
dome covers.

7. Railways may engage with oil loading parties/ oil companies under their jurisdiction to
progressively switch over to nonmetallic seals, so that chances of electrical tracking
(due to human failures) and consequential fires are reduced.

8. While on the subject, it is imperative to ensure the presence of gasket to RDSO

drawing No. W/TF-2169 on the dome cover, as the same provides a sealing protection
to possibility of product vapours emanating from the sampling pipes, filling pipes and
vapour extractor cocks.
TABLE 9.5

LIST OF RDSO MAINTENANCE PUBLICATIONS FOR TANK

WAGONS

Sr. Description Name of

No. Manual/Publication
1. Instructions for operation and maintenance of Bogie G-71/June-92
Phosphoric Acid tank wagon “BTPH”
2. Instruction for operation and maintenance for G-79
BTAL/BTALN
3. Instruction for operation and maintenance BG bogie G-82/1988
tank wagon for Alumina type “BTAP”.
4. Maintenance manual for bogie liquified petroleum gas G-86/1994 Rev.-1
tank wagon type BTPGLN.
5. Safe handling of Hazardous chemicals transported in G-87
Rail Tankers
6. Instructions for Maintenance & operation for bogie G-90
petrol tank wagon type “BTPN”
7. Instructions for Operation and Maintenance of Bogie G-83/1988
caustic soda tank wagon type “BTCS”