Section 5 Loose gear

5.1 Shackles

5.1.1 The safe working load of any shackle securing a block is to be not less than the SWL marked on the block, except in the case of single sheave blocks where the SWL is to be not less than twice that marked on the block.

5.1.2 The safe working load of any shackle used in another location is to be not less than the resultant load on the shackle.

5.1.3 Mild steel shackles are to be normalised after forging and before tapping and screwing. Higher tensile and alloy steel shackles are to be subjected to a suitable heat treatment.

5.1.4 Standard dimensions of Dee and Bow shackles are given for reference in Table 8.5.1 Dimensions of Dee shackles and Table 8.5.2 Dimensions of Bow shackles for the arrangements illustrated in Figure 8.5.1 Shackles.

Table 8.5.1 Dimensions of Dee shackles

Safe working load, in tonnes			Mild steel		Higher tensile steel
Safe working load, in tonnes	a	b	d ₁	d ₂	d ₁	d ₂
1,0	20	44	13	15	11	12
1,6	25	55	17	19	13	15
2,0	28	62	19	21	15	17
2,5	31	69	21	24	17	19
3,2	35	78	24	27	19	21
4,0	40	87	26	30	21	23
5,0	44	97	29	33	23	26
6,3	50	109	33	37	26	29
8,0	56	123	37	42	29	33
10,0	63	138	41	47	33	37
12,5	70	154	46	53	36	42
16,0	79	174	52	60	41	47
20,0	89	195	59	67	46	52
25,0	99	218	65	75	51	59
32,0	112	247	74	84	58	66
40,0	125	275	83	94	65	74
50,0	140	308	92	106	72	83
63,0	157	346	104	119	81	93
80,0	177	390	117	134	91	105
Note 1. All dimensions are given in millimetres and are illustrated in Figure 8.5.1 Shackles. Note 2. Higher tensile steel is defined as steel having a tensile strength not less than 540 N/mm². Note 3. Diameter d ₃ is to be not less than 2d ₂.

Table 8.5.2 Dimensions of Bow shackles

Safe working load, in tonnes				Mild steel		Higher tensile steel
Safe working load, in tonnes	a	b	2_r	d ₁	d ₂	d ₁	d ₂
1,0	20	50	34	14	16	12	13
1,6	25	63	43	18	20	15	16
2,0	28	70	48	20	22	17	18
2,5	31	78	53	23	25	18	20
3,2	35	89	60	25	28	21	22
4,0	40	99	67	28	31	23	25
5,0	44	111	75	32	35	26	28
6,3	50	124	84	36	39	29	32
8,0	56	140	95	40	44	33	36
10,0	63	157	106	45	49	36	40
12,5	70	175	119	50	55	41	44
16,0	79	198	135	56	62	46	50
20,0	89	221	150	63	69	51	56
25,0	99	248	168	70	77	57	63
32,0	112	280	190	80	87	65	71
40,0	125	313	213	89	98	72	79
50,0	140	350	248	99	109	81	89
63,0	157	394	267	112	123	91	100
80,0	177	444	301	126	138	102	112
Note 1. All dimensions are given in millimetres and are illustrated in Figure 8.5.1 Shackles. Note 2. Higher tensile steel is defined as steel having a tensile strength not less than 540 N/mm². Note 3. Diameter d ₃ is to be not less than 2d ₂.

Figure 8.5.1 Shackles

5.1.5 Where the shackle is not manufactured in accordance with a recognised Standard, the safe working load may be taken as the lowest of the values derived from the following formulae:

Side of body:

Crown of body:

Shackle pin:

where all dimensions are in millimetres and are illustrated in Figure 8.5.1 Shackles. The value of c is given in Table 8.5.3 Values of c for shackles.

Table 8.5.3 Values of c for shackles

Minimum tensile strength of steel, in N/mm²	c
Minimum tensile strength of steel, in N/mm²	Side	Crown	Pin
330	0,0076	0,0082	0,0072
430	0,0105	0,0113	0,0099
540	0,0140	0,0151	0,0132

5.2 Hooks

5.2.1 The safe working load of a hook is the maximum load that the hook is certified to lift in service.

5.2.2 Hooks may be of the ‘C’ or Liverpool type or of the double armed Ramshorn type, as indicated in Figure 8.5.2 Hooks. In general, ‘C’ type hooks are not to be used for safe working loads exceeding 25t. Hooks manufactured to recognised National or International Standards could be accepted based on manufacturer’s certification confirming the SWL and proof load as per Ch 12 Testing, Marking and Surveys of the Code. Hooks with a SWL beyond those given in Table 8.5.4 Dimensions of higher tensile steel ‘C’ hooks or Table 8.5.5 Dimensions of higher tensile steel Ramshorn hooks and/or hooks which do not comply with a recognised National or International Standard will be specially considered.

Figure 8.5.2 Hooks

Table 8.5.4 Dimensions of higher tensile steel ‘C’ hooks

Safe working load, in tonnes	a	b	c	D	H	M	G
1,0	124	78	6	31	26	17	17
1,6	156	98	8	39	33	21	20
2,0	176	110	8	44	37	24	25
2,5	196	123	10	49	41	27	25
3,2	219	138	12	55	46	30	30
4,0	247	156	12	62	52	34	30
5,0	279	176	14	70	59	38	35
6,3	311	196	16	78	66	43	40
8,0	351	221	18	88	74	48	45
10,0	391	246	20	98	82	54	50
12,5	439	276	22	110	92	60	55
16,0	495	311	24	124	104	68	60
20,0	555	349	28	139	117	76	70
25,0	622	392	32	156	131	86	80
Note 1. All dimensions are given in millimetres and are illustrated in Figure 8.5.2 Hooks. Note 2. Minimum material tensile strength σ_u 540 N/mm².

Table 8.5.5 Dimensions of higher tensile steel Ramshorn hooks

Safe working load, in tonnes	a	b	c	D	H	M	G
20	238	457	30	121	113	76	89
25	267	511	33	133	126	86	102
32	299	567	37	146	143	97	114
40	329	616	41	162	155	108	127
50	365	683	46	178	174	117	140
63	408	745	51	194	195	132	144
80	452	813	57	213	216	146	152
100	498	883	64	229	241	162	165
Note 1. All dimensions are given in millimetres and are illustrated in Figure 8.5.2 Hooks. Note 2. Minimum material tensile strength σ_u 540 N/mm².

5.2.3 Hooks are to be forged from killed steel with suitable mechanical properties and heat treatment conditions. Cast hooks are not generally permitted but special consideration will be given on a case-by-case basis to proposals for cast hooks that are manufactured in accordance with recognised National or International Standards. The following information is to be included in the proposal:

proposed material specification including the applicable National or International Standard, material grade, chemical composition, and mechanical properties and heat treatment conditions;
stress and fatigue calculations supporting the proposal; and
proposed surface and volumetric NDE specification, procedure and acceptance criteria including the technical justification of the criteria, i.e. casting simulations showing the potential casting defect area and/or calculated tolerable defect size based on engineering assessment.

Other manufacturing methods, such as additive manufacturing, will require special consideration.

5.2.4 ‘C’ type hooks are to be so designed as to reduce as far as possible the risk of the hook catching on an obstruction when hoisting and also the risk of the displacement of the load. An adequate safety catch is to be fitted across the jaw on all ‘C’ hooks.

5.2.5 Standard dimensions of ’C’ type and Ramshorn hooks are given in Table 8.5.4 Dimensions of higher tensile steel ‘C’ hooks and Table 8.5.5 Dimensions of higher tensile steel Ramshorn hooks respectively for the arrangements as illustrated in Figure 8.5.2 Hooks.

5.2.6 Where the hook is not manufactured in accordance with a recognised Standard, the safe working load may be taken as:

SWL

c k (H – 0,1D)²

where

the dimensions are measured in millimetres and are illustrated in Figure 8.5.2 Hooks. The values of c and kare to be obtained from Table 8.5.6 Values of c for hooks and Table 8.5.7 Values of k for hooks .

Table 8.5.6 Values of c for hooks

Minimum tensile strength of steel, in N/mm²	c
Minimum tensile strength of steel, in N/mm²	’C’ hooks	Ramshorn hooks
430	0,0011	0,0016
540	0,0015	0,0021

Table 8.5.7 Values of k for hooks

	θ
M/H	40°	30°	25°	20°	15°	10°	5°	0°
0,55	0,48	0,75	0,85	0,92	0,98	1,03	1,06	1,10
0,65	0,82	1,01	1,08	1,12	1,16	1,20	1,23	1,27
0,75	1,07	1,18	1,22	1,27	1,30	1,34	1,37	1,40
0,85	1,16	1,30	1,33	1,36	1,40

5.2.7 The hook shank is to be such that the direct tensile stress complies with Table 8.3.3 Allowable stresses in blocks. Alternatively, the allowable stresses for the hook shank may be calculated using the approach as defined in Ch 8, 3.5 Hook blocks. Detailed design is to be such as to minimise stress concentrations and in particular at the end of the threaded section. Shanks are to be forged from killed steel with suitable mechanical properties and heat treatment conditions. Cast shanks are not generally permitted but special consideration will be given on a case-by-case basis to proposals for cast shanks (reference is made to Ch 8, 5.2 Hooks 5.2.3.(a) to Ch 8, 5.2 Hooks 5.2.3.(c)). Other manufacturing methods, such as additive manufacturing, will require special consideration.

5.2.8 The safe working load for Ramshorn hooks, derived in accordance with this Section, is appropriate for sling legs at an included angle not exceeding 90°. No increase in SWL is permitted for lesser included angles.

5.2.9 Hooks for special purposes, such as for lifting freight containers, are to comply with appropriate recognised National or International Standards.

5.3 Swivels and lifting eyes

5.3.1 The safe working load of the swivel or lifting eye is to be equal to the maximum load for which the item is certified.

5.3.2 Lifting eyes and lug fittings as detailed in this Section may be used in association with swivel bow pieces or with another item of loose gear such as a cargo block.

5.3.3 Swivels are to be fitted with plain bearings or with ball or roller thrust bearings.

5.3.4 Triangular lifting eyes are to be designed for an included angle between the sling legs not exceeding 90° and they are not to be used for single point loading. Ball or roller thrust bearings are to be incorporated in the swivel arrangements.

5.3.5 Standard dimensions for mild steel, swivel bow pieces, round, oval and triangular eyes and lug fittings are given in Table 8.5.8 Dimensions of bow pieces for swivels to Ch 8, 5.3 Swivels and lifting eyes 5.3.5 for the arrangements illustrated in Figure 8.5.3 Bow piece for swivel to Ch 8, 5.3 Swivels and lifting eyes 5.3.5.

Table 8.5.8 Dimensions of bow pieces for swivels

Safe working load, in tonnes	a	b	d ₁	d ₂	e
1,0	37	64	13	20	20
1,6	46	80	16	25	25
2,0	53	92	18	25	29
2,5	60	104	21	30	32
3,2	67	116	23	30	36
4,0	74	128	26	35	40
5,0	83	144	29	40	45
6,3	92	160	32	40	50
8,0	104	180	36	45	56
10,0	117	204	41	55	64
12,5	131	228	46	60	71
Note All dimensions are given in millimetres and are illustrated in Figure 8.5.3 Bow piece for swivel.

Table 8.5.9 Dimensions of round and oval eyes

Safe working load, in tonnes	Shank	Round		Oval
Safe working load, in tonnes	d ₁	d ₂	d ₃	b	g	d ₄	e
1,0	M18	11	24	48	21	12	14
1,6	M22	14	30	58	26	16	18
2,0	M24	16	34	58	26	16	18
2,5	M27	18	39	72	32	21	23
3,2	M30	20	44	72	32	21	23
4,0	M33	22	48	94	40	26	28
5,0	M36	25	54	94	40	26	28
6,3	M42	27	60	108	45	29	32
8,0	M45	31	68	115	49	32	35
10,0	M52	35	76	125	54	36	39
12,5	M56	39	86	144	60	41	44
16,0	M64			163	66	46	49
20,0	M72 × 6			173	72	56	54
25,0	M76 × 6			192	80	56	59
32,0	M80 × 6			216	90	60	64
40,0	M90 × 6			240	100	66	70
50,0	M100 × 6			264	110	74	78
63,0	M110 × 6			290	120	84	89
80,0	M120 × 6			325	135	94	99
100,0	M130 × 6			360	150	105	111
Note All dimensions are given in millimetres and are illustrated in Figure 8.5.4 Round the oval eyes.

Table 8.5.10 Dimensions of triangular lifting eyes

Safe working load, in tonnes	Shank			Top		Side		Bottom
Safe working load, in tonnes	d ₁	a	b	e	f	g	h	j	k
20	M72 x 6	475	400	48	95	66	95	94	95
25	M76 x 6	515	445	51	108	72	108	100	108
32	M80 x 6	565	500	55	120	79	120	108	120
40	M90 x 6	630	550	59	133	86	133	117	133
50	M100 x 6	675	600	64	146	94	146	127	146
63	M110 x 6	740	660	71	150	104	150	139	150
80	M120 x 6	815	725	78	158	115	158	153	158
100	M130 x 6	880	795	86	178	127	178	168	178
Note All dimensions are given in millimetres and are illustrated in Figure 8.5.5 Triangular lifting eye.

Table 8.5.11 Dimensions of lug fittings

Safe working load, in tonnes	Shank
Safe working load, in tonnes	d ₁	a	b	d ₂	d ₃
1,0	M18	19	8	17	35
1,6	M22	23	11	21	45
2,0	M24	26	12	23	50
2,5	M27	29	13	25	55
3,2	M30	32	14	28	60
4,0	M33	35	15	31	65
5,0	M36	39	18	37	75
6,3	M42	45	20	40	85
8,0	M45	49	23	46	95
10,0	M52	58	26	50	110
12,5	M56	64	28	54	120
16,0	M64	70	30	62	130
20,0	M72 × 6	74	33	70	140
25,0	M76 × 6	80	35	74	150
32,0	M80 × 6	90	40	82	170
Note All dimensions are given in millimetres and are illustrated in Figure 8.5.6 Lug fitting.

Figure 8.5.3 Bow piece for swivel

Figure 8.5.4 Round the oval eyes

Figure 8.5.5 Triangular lifting eye

Figure 8.5.6 Lug fitting

5.3.6 Items whose dimensions differ from those given in Table 8.5.4 Dimensions of higher tensile steel ‘C’ hooks may be designed in accordance with the requirements given in Table 8.5.12 Swivels and eyes and Table 8.5.14 Form factors, K .

Table 8.5.12 Swivels and eyes

Item	Safe working load, in tonnes
Swivel bow piece
	where b < 2,55d ₁, this value is to be multiplied
	by 0,22
Round eye
	where d ₃ < 2,55d ₂, this value is to be multiplied
	by 0,22
Oval eye
	where b < 2,55d ₄, this value is to be multiplied
	by 0,22
Triangular eye	Top	0,0069e f
	Side
	Bottom
Lugs	0,0125b (d ₃ – d ₂)
Shank	c d ₁ ²
Note 1. All dimensions are given in millimetres and are illustrated in Figure 8.5.3 Bow piece for swivel. Note 2. Values of c and K are given in Table 8.5.13 Values of c for swivel and eyes and Table 8.5.14 Form factors, K respectively.

Table 8.5.13 Values of c for swivel and eyes

Item	c
Item	Mild steel	Higher tensile steel
Swivel bow piece	0,0066	0,0088
Round eye	0,0176	0,0236
Oval eye	0,0057	0,0076
Shank	0,00493	0,00625
Note Higher tensile steel is defined as steel having a tensile strength not less than 540 N/mm².

Table 8.5.14 Form factors, K

Shape of section		K
Square	H = B	1,00
Circular	H = B	0,66
Rectangular	H = 0,75B	0,95
Rectangular	H = 0,50B	0,90
Radius at intrados and extrados	H = 0,90B	0,80
Radius at intrados only	H = 0,70B	0,75
Ellipse	H = 1,25B	0,66
	H = 0,75B	0,65
	H = 0,50B	0,64
Semi-circle	H = 0,50B	0,64
Note Values for intermediate shapes may be obtained by interpolation.

5.4 Chains, links and rings

5.4.1 The overall dimensions of the links of chain are to be within the limits in Table 8.5.15 Link chain limits.

Table 8.5.15 Link chain limits

	Length	Breadth
Short link	4,5d – 5,0d	3,25d – 3,5d
Long link	7,0d – 9,0d	3,25d – 3,5d
Symbols
d =nominal diameter of the chain

5.4.2 The certified safe working load of short or long link chain is not to exceed the values derived from Table 8.5.16 Safe working load of chain. Proposals for the use of alloy steel chains will be specially considered.

Table 8.5.16 Safe working load of chain

Item and material		Safe working load, in tonnes
Short link
	Mild steel	0,0094d ₂
	Higher tensile steel	0,0125d ₂
	ISO Grade 40	0,0161d ₂

Long link
	Mild steel	0,0063d ₂
	Higher tensile steel	0,00825d ₂
Note 1. Where d is the nominal diameter of the chain, in mm. Note 2. ISO Grade 40 chain is to comply with the requirements of ISO/R 1834, 1835 and 1836 as appropriate.

5.4.3 The safe working load for links or rings is to be not greater than the value obtained from Table 8.5.17 Safe working load of links and rings.

Table 8.5.17 Safe working load of links and rings

Item	Safe working load, in tonnes
Swivel bow piece
	where b < 2,55d, this value is to be multiplied
	by 0,22
Rings
	where a < 2,55d, this value is to be multiplied
	by 0,22
Note 1. All dimensions are measured in millimetres and are illustrated in Figure 8.5.7 Chain link and ring. Note 2. The value of c is obtained from Table 8.5.18 Values of c for links and rings .

Figure 8.5.7 Chain link and ring

Table 8.5.18 Values of c for links and rings

Minimum tensile strength of material, in N/mm²	Value of c
Minimum tensile strength of material, in N/mm²	Links	Rings
430	0,0053	0,0116
540	0,0071	0,0155

5.5 Miscellaneous items

5.5.1 The triangle plate for use with a span chain or with union purchase cargo runners is to be provided with three holes of diameter not less than 1,25 times the diameter of the associated shackle pin. One of the holes may be extended as a slot to facilitate reeving of the shackle.

5.5.2 The corners of the plate are to be radiused. The corner radius, measured from the centre of each hole is to be not less than the diameter of the hole. The thickness of the plate is to be not less than one half the width of the jaw of the associated shackle. The radius of the corners and thickness of the plate are to be such that, when subjected to the safe working load, the mean tensile stress in the material around the hole does not exceed (25 + SWL) N/mm², where the SWL is measured in tonnes.

5.5.3 Where a union purchase swivel assembly is formed of a ring to which the hook and runners are connected by swivels, the ring is to comply with Ch 8, 5.4 Chains, links and rings 5.4.3.

5.5.4 Tubular bodies and end fittings of rigging screws are to be of steel having a tensile strength not less than 350 N/mm². The tensile stress in the body and in the shanks of the end fittings is not to exceed (25 + SWL) N/mm², where SWL is the safe working load, in tonnes, of the rigging screw.