Safe cable guidance for sheerleg cranes with cable weights of up to 45kg/m

Profile

• What was needed: E4/4-series energy chains in a gliding and a roller energy chain design
• Requirements: Long travels, high cable weights, high travel speed and acceleration, highly corrosive environment at sea
• Industry: Offshore, cranes
• Success for the customer: The heavy-duty energy chains are designed as multiband chains and bear the high additional loads without any problems. In one case, where the solution was designed as a roller energy chain, the required drive energy is significantly less and wear is reduced.

Problem

Sheerleg cranes are now indispensable for building ships and other structures such as bridges. Equipped with an A-frame, some offshore cranes can lift loads of several thousand tons.
Absolutely reliable components must therefore be used to guide sensitive cables for power and data to the adjustable crane boom. In addition to typical conditions at sea, such as aggressive corrosion and strong wind, there are additional requirements depending on the sheerleg crane design. In large-dimensioned heavy-duty cranes, travels are especially long and cable weights to be moved are correspondingly high. In these two sheerleg projects, the planners were therefore looking for low-wear, continuously safe cable guidance systems that can ensure a high level of planning reliability.

Solution

In both projects, the E4/4 plastic energy chain system, which is designed for the offshore sector, is used as an extension-link e-chain for high additional loads. The specific loads of 34.6kg/m and 45kg/m are reliably moved with these heavy duty energy chains over the travels of 54m and 74.4m, respectively. The chain accelerates at up to 1.0 m/s², reaching travel speeds of 1.0m/s and 1.2m/s, respectively. In the latter application, the cable guidance system was even designed as a roller energy chain for even less friction than the gliding version, reducing drive power to less than 25% of that for the gliding version and thus also ensuring a high level of planning reliability for large cranes. They are also designed as plastic energy chains, particularly suitable for offshore applications, since they have a low dead weight and are corrosion-resistant.