ETA/ETC/ETM Ref.

: T-6054
GB
Snatch blocks for wire rope Revision: 8
TECHNICAL SHEET heavy duty off-shore Date: 11.2022

APPLICATIONS
The snatch blocks of the ETA/ETC/ETM’s range are mainly used for temporary applications for pulling and lifting,
when quick assemblies and/or dismantlings are required. They can be suspended to a fixed or mobile anchorage
point with the right strength corresponding to the required load. Thanks to an easy instalment, a light weight and
attached locking parts, these snatch blocks are most often used on vessels and off-shore platforms.

ETM – snatch block with shackle ETC – snatch block with hook ETA – snatch block with axle

DESCRIPTION
The snatch blocks are available in 3 models with 3 different types of anchorage:
▪ ETC model with a hook with safety latch for a quick transfer,
▪ ETM model with a swivel shackle for an optimised and secured anchorage,
▪ ETA model with an axle suitable for tiny spaces.

The ETC and ETM models can easily be transformed in an axle model (ETA) by using standard tools.
Once the snatch block is not under tension, the opening, operated by turning one bearing flange around the
sheave axle, makes the introducing of the wire rope in the groove possible, while the block remains
suspended. All the parts stay interdependent during the flange opening and the wire rope introduction.
The locking axle is secured by a safety pin which prevents any unscrewing or uncontrolled movement.

TECHNICAL CHARACTERISTICS
▪ Ultimate load is 4 times the working load limit (WLL).
▪ Zinc bichromated coating for capacities up to 8 tons. Above yellow painted in Ral 1004.
▪ The sheaves are fitted either on bronze bush or on ball or roller bearing (Please refer to the
enclosed table)
▪ Pressure axial lubrication on all the models, except the 2 tons model with a self lubricated
bush.

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 ETA/ETC/ETM Ref.: T-6054
GB
Snatch blocks for wire rope Revision: 8
TECHNICAL SHEET heavy duty off-shore Date: 11.2022

DIMENSIONAL CHARACTERISTICS
sheave Ø rope Ø height Cotes hors tout weight
WLL1 F E C I O D
H T W hook/ shackle pin bearing
BOGØ (2) ETXØ min.max Ø hook shackle axle
t mm kg
2 60 79 9/10 218 219 92 285 92 84 30 33 2.7 1.6 Bba2
5 90 114 12/14 318 327 142 424 125 124 39 51 8 4.5 Bb3
5 140 165 12/14 369 378 167 475 125 175 39 51 10.5 7 Bb
8 112 142 17/19 397 400 182 529 162 152 48 58 15 8.5 Bb
8 177 209 17/19 431 434 216 567 162 220 48 58 20 13.5 Bb
8 221 262 17/19 457 460 245 649 162 272 48 58 25 18 Ro4
8 275 326 20/23 495 498 283 718 162 336 48 58 29 23 Ro
12.5 112 145 20/23 453 444 201 584 192 155 57 68 30 24 Bb
12.5 174 216 20/23 488 479 236 655 192 226 57 68 35 28 Ro
12.5 174 216 26/29 497 488 245 664 192 226 57 68 35 28 Bb
15 221 262 20/23 560 574 270 765 220 272 57 83 38 30 Ro
15 275 326 20/23 592 607 302 828 220 336 57 83 45 36 Ro
15 355 420 20/23 639 653 349 896 220 430 57 83 65 52 Ro
20 174 216 26/29 553 576 260 664 192 226 44 89 39 31 Ro
20 224 268 35/38 583 606 260 789 192 278 44 89 56 45 Ro
20 349 410 35/38 653 676 360 930 192 420 44 89 70 56 Ro
25 221 262 26/29 648 665 296 865 218 272 52 98 62 48 Ro
25 270 326 26/29 680 697 628 929 218 336 52 98 85 63 Ro
32 270 334 42/46 713 761 359 798 245 344 59 110 95 70 Ro
32 443 518 42/46 805 853 451 900 245 528 59 110 135 100 Ro

1 Working Load Limit

2 Bottom Of Groove
3 Self lubricated bush
4 Bronze bush
5 Ball or roller bearing
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www.tractel.com
 ETA/ETC/ETM Ref.: T-6054
GB
Snatch blocks for wire rope Revision: 8
TECHNICAL SHEET heavy duty off-shore Date: 11.2022

REFERENCES
hook hook Reference
F E C
WLL (1) Group
BOGØ (2) ETXØ min.max Ø hook Group code shackle Group code axle
code
mm
2 60 79 9/10 ETC2-79E10 81429 ETM2-79E10 81439 ETA2-79E10 81449
5 90 114 12/14 ETC5-114E14 81399 ETM5-114E14 81409 ETA5-114E14 81419
5 140 165 12/14 ETC5-165E14 81459 ETM5-165E14 81469 ETA5-165E14 81479
8 112 142 17/19 ETC8-142E19 81489 ETM8-142E19 81499 ETA8-142E19 81509
8 177 209 17/19 ETC8-209E19 81519 ETM8-209E19 81529 ETA8-209E19 81539
8 221 262 17/19 ETC8-262E19 81549 ETM8-262E19 81559 ETA8-262E19 81569
8 275 326 20/23 ETC8-326E23 81579 ETM8-326E23 81589 ETA8-326E23 81599
12.5 112 145 20/23 ETC12-145E23 81608 ETM12-145E23 81619 ETA12-145E23 81629
12.5 174 216 20/23 ETC12-216E23 81669 ETM12-216E23 81679 ETA12-216E23 81689
12.5 174 216 26/29 ETC12-216E29 81639 ETM12-216E29 81649 ETA12-216E29 81659
15 221 262 20/23 ETC15-262E23 81699 ETM15-262E23 81709 ETA15-262E23 81719
15 275 326 20/23 ETC15-326E23 81759 ETM15-326E23 81769 ETA15-326E23 81779
15 355 420 20/23 ETC15-420E23 81819 ETM15-420E23 81829 ETA15-420E23 81839
20 174 216 26/29 ETC20-216E29 81729 ETM20-216E29 81739 ETA20-216E29 81749
20 224 268 35/38 ETC20-268E38 81789 ETM20-268E38 81799 ETA20-268E38 81809
20 349 410 35/38 ETC20-410E38 81849 ETM20-410E38 81859 ETA20-410E38 81869
25 221 262 26/29 ETC25-262E29 81879 ETM25-262E29 81889 ETA25-262E29 81899
25 270 326 26/29 ETC25-326E29 81939 ETM25-326E29 81949 ETA25-326E29 81959
32 270 334 42/46 ETC32-334E46 81909 ETM32-334E46 81919 ETA32-334E46 81929
32 443 518 42/46 ETC32-518E46 81969 ETM32-518E46 81979 ETA32-518E46 81989

NON-CONFORM USES
▪ NEVER USE FOR PERSONNEL LIFTING.
▪ Strictly forbidden to either be under or to walk under the load.
▪ The block should be regularly inspected (priory checking parts correctly assembled, no excessive
movement, no excessive wearing or corrosion, no deformation, no weld corrosion or cracking,
free rotating sheave).
▪ Prior to using the block, check for proper position and locking of the axles. Threaded axle head
should be visible after application of nuts.
▪ Never use a block with a hook as headfitting without ensuring that the safety latch is correctly
operated and free from deformation.
▪ For lifting operations, the user must refer to the safety rules and regulations applicable to this use.

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 ETA/ETC/ETM Ref.: T-6054
GB
Snatch blocks for wire rope Revision: 8
TECHNICAL SHEET heavy duty off-shore Date: 11.2022

WIRE ROPE STRENGTH REDUCTION

Pitch Ø (= BOG Ø + 1 w/r Ø) i
The ratio Wire rope Ø between the pitch diameter of the sheave and the wire rope
diameter, called the winding ratio, alters the tensile strength in the wire rope as hereafter:

Winding ratio Reduction

6 21%
8 17%
10 14%
15 11%
20 9%

Above values are given for information only, depending on the construction of the wire rope.
For more information, please ask your wire rope supplier.

MAXIMAL EFFORT APPLIED ON THE HEADFITTING OF THE BLOCK

The maximal effort applied on the suspension depends on the load and on the α angle formed between the
fall of the load and the fall on which this effort is applied.

The resultant value must be strictly lower to the working load limit of the block and the resistance of
the anchorage point where the block is fitted.

Please refer to the table and sketch hereunder indicated:

Suspension effort
α angle Effort applied on the
suspension
0° Winch WLL x 2
15° Winch WLL x 1.98
30° Winch WLL x 1.95
45° Winch WLL x 1.85
60° Winch WLL x 1.73
90° Winch WLL x 1.41
120° Winch WLL x 1
150° Winch WLL x 0.52
180° 0

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