Technical Specification for safety stairways
1.1 General Details
1. Nos. of Steps- Three Steps or Four steps as per site conditions. Vendor shall visit the site
and assess suitably the site requirements and quote and design accordingly
2. Width of Clear Passage = 610 mm to 800 mm
3. Load Capacity = Minimum 250 Kgs
4. Minm. Approach Length in Horizontal plan = 1200 mm (or as per site requirement with
approval from HPCL EIC)
5. Safety stairways to be provided with Auto Parking Lock
6. Material of Construction: Assembly shall be made of Aluminum T 6063 Alloy. High Tension
structural steel IS 2062 for non -moving base step, SS wire rope, and Aluminum for hand
Rail shall be used. Vendor should make sure that under no condition any sparking situation
develops while operating the staircase.
7. Balanced by Spring Cylinders (Pressure Spring) on both sides. It should also have provision
for setting spring tension.
8. Handrails to be provided for stairways for safe and easy movement of persons.
9. First Step with Safety Guidance Shield (Non Moving Step) and balance self-leveling designed
Steps.
10 Steps will be of Anti-Skid type made of Aluminum.
11. Contact Bracket, covered with an Oil Resistant Rubber Bumper if required. However, the
staircase should be self-supporting and should not be resting on the Tank truck during
operation while at the same time should be safely designed to carry minimum static load
of 250 Kg without support.
12. Guide Arms (Handrails) made of Aluminum pipes duly painted on the basis of advice from
HPCL EIC.
13. Stairways to be provided with maintenance free Bearing for majority of the rotating joints.
14. Proper Locking device (Arresting Device) or arrangement should be designed in such a way
that it should get locked on Maximum opening of Steps.
15. All the accessories required for installation of safety staircase like nuts, bolts etc. to be
provided by vendor.
16. APPLICABILITY:
The retractable stairs shall be provided at following facility:
• Tank Truck Gantry ( TT Gantry) at HPCL IRUMPANAM TERMINAL.
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Note: The retractable stairs shall be installed at above locations after ascertaining the
structural stability and space availability at existing locations.
1.2 DETAILED SPECIFICATION FOR RETRACTABLE STAIRS:
1. The assembly provided shall be full Factory fabricated, assembled, tested, crated
selfretractable & self-supporting folding stair with required Tension spring
assembly and HD safety chains. The static load capacity of the assembly should be
designed for a minimum of 250 Kg. The assembly should not contain any maintenance
bearings & bushings
2. The assembly shall be constructed with Aluminum T 6063 Alloy to prevent any spark due
to contact with TT/TW or the Gantry structure. The stair assembly shall consist of the
following minimum features/ components:
a. Base frame made of C channel of 130 or 200 mm height as per the gantry
loading platform dimensions, Cross bar reinforcement for the underside of the
staircase frame to prevent tilt & bend/ twist during operation.
b. 2 nos Tension spring enclosed in an assembly to prevent damage/injury due to
breakage of the springs.
e. Nonmoving Base step (Mild Steel as per lS 2062 and Hot Dip Galvanized to 360
grn/sqm) with clear width of 610~800 mm between the hand rails. Treads shall
be minimum 300 mm wide with non slip serrated pattern on the treads. The
number of moving steps varying from (1+2) option to (1+6) option to be decided
by the location as per requirement based on existing Gantry structure height,
Tank trucks operating in the location or height of tank wagons etc. The moving
Steps (Aluminum) shall be self-leveling type with a suitable stopper or locking
device to keep the steps in horizontal position under loaded conditions. Number
of Steps Three Steps or Four steps should be as per site conditions. Vendor has
to visit the site and assess suitably the site requirements and design accordingly.
c. Adjustable spring box on either side of the staircase for flexible balancing
between (-)40 to (+)45 degree. Parking position to be designed at 85 degree to
avoid collision with TT/ TW.
d. Hand railing arrangement with a mid-rail made of flat, hand rail & top hand rail
made of pipe for comfortable grip while walking on stairs & for ease of lowering
and raising operation to reach the top of TT/ TW etc.
e. Adjustable chain stops with easy locking arrangement to support load up to 250
kg at last stair with Self-supporting design. SS wire rope of 8 mm dia.
(min)/equivalent with rubber shrouds/ grip to pull the staircase comfortably into
the parking position with a single hand effort.
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f. Automatic foot lock to keep the stair case in parking position when not in
operation. Padded lower edge with rubber bumper or rubber fender of
appropriate thickness to protect the TT/ TW surface.
g. Construction of all rotating joints shall be to avoid friction & static sparking.
h. Safety Cage with Sing gate need not be provided as part of the Stair assembly
since a separate life line based fall protection system is adopted. However, the
design & construction should permit fixing of the safety cage at a later date if
required.
i. Painting & Finishing: Pickling & Passivation for Aluminum & structural parts with
minimum coating thickness of 25 µm (Average) & 20 µm (Local) as per latest
edition of IS 1868 or equivalent standards such as ASTM B580, ASTM 3933, lSO
10074, applicable DlN, EN Standards.
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Retractable Safety Staircase for HPCL
Reference Drawing of the staircase.
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