High-strength fibre rope soLITE® for crane operation

High-strength fibre rope soLITE® for crane operation2

Motivation and development

High-strength fibre rope soLITE® for crane operation 3

Together with the Austrian rope manufacturer Teufel-berger Holding AG, Liebherr is developing a new type of high-strength fibre rope for hoisting operations. Whether tower, mobile, crawler, or maritime cranes, this new de-velopment of a high-strength fibre rope will in future be re-placing the steel rope in a wide range of crane operations. This project is based on a systematic cooperative venture between Liebherr engineers from various divisions, includ-ing Liebherr-Components Biberach GmbH, as well as the three Liebherr manufacturing plants for tower cranes, mobile and crawler cranes, and maritime cranes in Biber-ach, Ehingen, and Nenzing. Currently, the ropes are un-dergoing tests on both the bench and on a number of Liebherr cranes in field trials.

Reasons behind the developmentThe practical requirements of cranes with increasingly higher hoisting heights and maximum load capacities re-quire a realignment in the rope and crane design. The high-strength fibre rope soLITE® developed after many years of collaborative work is based on the vast experience of Liebherr in rope applications and the in-depth know-how of Teufelberger in the development and manufacture of fibre and steel ropes.

Status of developmentUp to now, Liebherr has tested a big number of rope de-signs on several test benches for a total duration of about 45.000 hours. These tests were conducted specifically on multi layer drum windings and reverse bending strength. The total rope length tested was about 50.000 m. The result is a high-strength fibre rope that fulfils all of the specified require-ments:

Achieved targets• Maximum weight savings of about 80 % compared with a steel rope• Easy reeving and unreeving operations.• Less rope weight for increasing load capacities,

especialy for big lifting heights• Maritime cranes can lower loads to considerably greater

water depths• Reduced hook block weight• Reduced transport weight• Smooth-running multi layer windings on the drum.• No rope lubrication needed; no soiling on vehicle cranes’

front windows• Long service life• Clear discard criteria

Images page left: Test centre for rope and rope drive development, Liebherr-Components Biberach GmbH

High-strength fibre rope soLITE® for crane operation4

Lower rope weight

09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

0,5

1

1,5

2

2,5

3

3,5

4

4,5

5

(Ø 10)

(Ø 20)

(Ø 27)

0,08 (Ø 10)0,31 (Ø 20)0,58 (Ø 27)

Rope weight [kg/m]

Ste

el r

op

e (Ø

)

Rope diameter [mm]

Weight savings when steel rope replaced with fibre rope soLITE®

soLITE® [kg/m (Ø)]

Weights compared per metreWhen the rope weight in kg / m is based on the rope diameter, the synthetic fibre rope soLITE® is five times lighter than a comparable steel rope.

Thanks to this lower rope weight, the crane can be assembled and disas-sembled quickly and easily. Fibre ropes can be mounted on the crane by hand and without any reeving winches.

Steel wire rope weights compared to soLITE® fibre ropes

High-strength fibre rope soLITE® for crane operation 5

Increased load capacityTower crane 280 EC-H 12 Litronic

00 10 20 30 40 50 60 70 80

2

4

6

8

10

12

14

Radius [m]

Load

cap

acity

[t]

2,5 t

12,5 t

12,0 t

Current load capacity with steel rope (LM1)

Increase to load capacity with the fibre rope soLITE® (LM1)

Load capacity with the fibre rope soLITE® (LM2)

+4,0%

+20,0%

+32,0%

3,0 t

3,3 t

Replacing the steel rope with the fibre rope soLITE® increases the load capacity of the tower crane 280 EC-H 12

Weight savings in rope and load hook serve to increase the maximum load capacity and the maximum load momentThis increase in performance becomes clear on the 280 EC-H 12, when it is used with the fibre rope and a lighter hook block. At a hook height of 60 m, these in-creases range from 4 % to 20 %; at 200 m, from 9,5 % to 58 %.

High-strength fibre rope soLITE® for crane operation6

Mobile crane LTM 1220-5.2 | LICCON 2

T 60 m

T 60 m

0 4 8 12 16 20 24 28 32 36 40 44 48 52 560

4

4

8

12

16

20

24

28

32

20

24

28

32

36

40

44

48

52

56

60

64

3,8 t

8,6 t

18,5 t

Load

cap

acity

[t]

Lift

ing

hei

ght

[m

]

Radius [m]

Increase to payload with the fibre rope soLITE®

Current payload with steel rope

+8,1%

9,3 t

+4,3%

19,3 t

+13,4%

4,3 t

22,5°45°

T 60 m

m

1680 24 32 40 48 56 64 72 80 m

24

32

40

48

56

64

72

80

88

96

m

88 92

104108

0,5

1,0

1,5

2,0

2,5

3,0

3,5

4,5

5,0

5,5

6,0

6,5t

Load

cap

acity

[t]

Lift

ing

hei

ght

[m

]

Radius [m]

+16,2%

3,2 t

2,7 t

1,7 t

+24%

2,1 t

0,2 t

Current payload with steel rope

Increase to payload with the fibre rope soLITE®

+163%

0,5 t

K 36 m

K 36 m

Weight savings in rope and hook block serve to increase the maximum payloadThe high-strength fibre rope serves to increase the payloads of the mobile crane LTM 1220-5.2 (T60, 3-reevings) by 4,3–13,4 %, depending on the radius.

Weight savings in rope and hook block serve to increase the maximum payloadOn the mobile crane LTM 1220-5.2 (T60, K36, 0°) with single- line, the high-strength fibre rope increases the payloads by 16,2–163 %, depending on the radius.

High-strength fibre rope soLITE® for crane operation 7

Crawler crane LR 1300

32

16 24

32

40

48

56

64

72

80

88

96

104

112

120

128 m

8

24

40

4850°

40°

60°56

64 t

Load

cap

acity

t [

t]

Radius -> 115 m

Lift

ing

hei

ght

[m

]

0 8 16 24 32 40 48 56 64 72 80 88 96 104112

Current payload with steel rope

Increase to payload with the fibre rope soLITE®

+9%

+71%

35 t

32 t

4,4 t2,6 t

70°

120 m120 m

117 m117 m

123 m123 m

Weight savings in rope and hook block serve to increase the maximum payloadOn the crawler crane LR 1300, the high-strength fibre rope increases the maximum payload by 9–70 %, depending on the radius.

High-strength fibre rope soLITE® for crane operation8

Lower hook block weight

The comparison: What weights is needed for the hook block if a steel or a high-strength fibre rope is used?Without attached load, the hook block must be heavy enough to be lowered from its highest position. Furthermore: To guarantee proper spooling on the drum the rope tension must be sufficient. The high-strength fibre rope (soLITE®) makes this considerably easier because it weighs about 80 % less than a comparable steel wire rope. The lower weight and the higher flexibility of soLITE® allows serve to reduce the hook block weight by about 50 %.

Each reduction in the hook block weight in turn increases the crane’s payload.

For the steel ropeHook block weight 100 % with additional ballast

For soLITE®

Hook block weight 50 % without additional ballast

High-strength fibre rope soLITE® for crane operation 9

LTM 1750-9.1Lower transport weightLTM 1220-5.2

Hoist ropesSteel rope Ø 23 mm High-strength fibre rope Ø 25 mmRope length for winch 1: 350 m Rope length for winch 1: 350 mRope weight: 910 kg (2,6 kg / m) Rope weight: 178 kg (0,51 kg / m)Weight savings: 732 kg

Hoist ropesSteel rope Ø 25 mm High-strength fibre rope Ø 27 mmRope length for winch 1: 700 m (760 m) Rope length for winch 1: 750 mRope weight: 2,107 kg (3,01 kg / m) Rope weight: 421 kg (0,56 kg / m)Rope winch weight: 1.300 kg Rope winch weight: 1.481 kgWeight savings: 1.505 kg

The weight savings can be used for reinforcing the bearing steel structure, keeping the crane’s total mass constant. Higher load capacities are therefore possible within the crane’s specifications. The re-duced weight of the reeving can be directly added to the capacity of the crane. Moreover, the lower hook block weight allows longer boom configurations, especially on lattice boom cranes.

The high-strength fibre rope reduces the transport weight, of the mobile crane LTM 1220-5.2 by approx. 0,7 t.

The high-strenght fibre rope reduces the transport weight of the LTM 1750-9.1 by approx. 1,5 t.

High-strength fibre rope soLITE® for crane operation10

Perfect winding of soLITE® on multilayer

drums and longer service lifetime

Increase to service life when steel rope replaced with fibre rope soLITE®

00,1 0,2 0,3 0,5 0,8 1 2 3 4 5 6 8 10

1.0002.0003.0004.0005.0006.0007.0008.0009.000

10.000

12.000

Full

load

lift

ing

/lift

ing

hei

ght

40

m/

sixf

old

ree

ving

Reference service life (fibre/steelsteel wire ropes rope)

Fibre rope service life under full load SF = 4,0

Steel rope service life under full load SF = 4,5

11.000

The high-strength fibre rope soLITE® developed by Liebherr and Teufelberger needs no lubrication. The high-strength fibre rope proves its advantages over its steel counterpart, specifically during disassemblies from large hoisting heights: Lifting an unloaded hook block spools the rope under a very low tension on the drum. Attaching the load at a great height induces a greater tension in the rope, causing it to cut into the lower layers. When using steel wire ropes, in extreme cases the actual rope pull will not be sufficient to pull the rope out of the lower layers – and it therefore becomes impossi-ble to lower the load. This is different for soLITE®: The high-strength fibre rope is likewise pulled into the lower layers, but thanks to its considerably lower jacket friction and lack of intermeshing with the adjacent windings, it can be extracted from these lower layers without damage.

Long service life of soLITE® winding on multilayer drumThe fibres used are extremely wear resistant and can un-dergo a large number of bending cycles. A comparison of full load lifting with steel wire ropes and high-strength fibre rope until full or strand break shows: Under the same, realis-tic bench tests on multi layer windings, the high-strength fibre rope achieves a service life up to thirteen times longer than the steel wire ropes in the medium temperature range.

High-strength fibre rope soLITE® for crane operation 11

State of Discard

Field Tests

Degree of damage approx 5 % Jacket with slight signs of wear

Degree of damage approx 90 % Wear on jacket circumference; approx 180° in some sections

Degree of damage approx 40 % Wear on single jacket strands

Degree of damage approx 100 % Whole jacket circumference worn

Degree of damage approx 75 % Wear on jacket circumference; approx 90° in some sections

In advance of the market launch, the high-strength fibre rope is tested in various machines of the Liebherr Group. The field tests are carried out on various tower cranes as well as on mobile and crawler cranes. This covers a wide range of appli-cations including operations in industrial plants, wind power installation and dismantling and construction applications.

The results of these tests are used in the development and optimization of the fibre rope and guarantee reliability of the product by meeting the customer's requirements.

Jacket wear, especially on multi layer windings, provides reliable identifications of the discard state for the fibre rope soLITE®

The crane operator can recognise easily and reliably when the rope must be replaced. The jacket wears in a prede-fined pattern, making the red supporting parts visible. The discarding state can therefore be recognised without aids before there is any damage to the rope’s load bearing parts.

The rope maintains 100 % of its load capacity, even where there is 50 % damage to the jacket.

The Liebherr Group of Companies

Wide Product RangeThe Liebherr Group is one of the largest construction equipment manufacturers in the world. Liebherr’s high- value products and services enjoy a high reputation in many other fields. The wide range includes domestic appliances, aerospace and transportation systems, machine tools and maritime cranes.

Exceptional Customer BenefitEvery product line provides a complete range of models in many different versions. With both their technical excellence and acknowledged quality, Liebherr products offer a maxi-mum of customer benefits in practical applications.

State-of-the-art TechnologyTo provide consistent, top quality products, Liebherr attaches great importance to each product area, its components and core technologies. Important modules and components are developed and manufactured in-house, for instance the entire drive and control technology for construction equipment.

Worldwide and IndependentHans Liebherr founded the Liebherr family company in 1949. Since that time, the enterprise has steadily grown to a group of more than 130 companies with over 41,000 employees located on all continents. The corporate headquarters of the Group is Liebherr-International AG in Bulle, Switzerland. The Liebherr family is the sole owner of the company.

www.liebherr.com

Liebherr-International Deutschland GmbH Postfach 16 58, D-88386 Biberach +49 7351 41-0, Telefax +49 7351 41-2650www.liebherr.com, E-Mail: info.lho@liebherr.com

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