Huisman-Itrec has completed construction of Mammoet’s third Platform Twin Ring Containerized (PTC) crane, a 1,600t capacity ring-mounted lattice boom rig.
The latest unit is now undergoing testing at Mammoet yard in Schiedam in the Netherlands. It will then go to Brazil for its first project – exchanging a refinery reactor near Santos.
With a maximum boom and jib combination length of 200m, the PTC is mainly designed for the erection of columns, Mammoet says. On full boom it can lift 190t out to a radius of 32m, with 1,500t maximum counterweight.
Main boom is 97.3m long and gross weight is 2,100t.
The key feature of the PTC cranes is that they can be broken down into sections that fit into 88 standard sized (20ft or 4ft) containers. This means that no special transport is required.
To simplify assembly of the crane, it has a double backmast and the winches remain reeved during transportation. To make reeving easier, the dead end of the wires is a swaged socket instead of open wedge sockets. The swaged socket is small enough to be reeved through all the sheaves without dismantling the socket. It is then connected to the dead end connection. Lebus drums aid smooth spooling.
The upper structure of the ring consists of two longitudinal beams, connected by quick connection pins to a transverse beam at the front. The power pack, lower ballast beam, upper ballast beam, several winches, backmast erection frame, boom stops and operator cabin are all mounted on the longitudinal beam. All components are a modular design and connected by quick connection pins to speed assembly.
It takes eight minutes for the crane to rotate 360 degrees. The winch speed is 80m/min.
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Material needed for a PTC
- 1,000t of steel for the structure
- 2,100m of cables for electrical installations
- 5,300m of 50.4mm wire rope
- 2,650m of 30mm wire rope
- 1,500t of steel for the counterweight
- 1280m of hydraulic hoses
- 6,000 litres of hydraulic oil
- 6,000 litres of paint
