It designed and manufactured a light crane system to lift replacement glass panels for a London office building.

The lifting equipment hung off scaffolding 26m (100ft) high.

In fact the company supplied two cranes. The first was a 350kg (775 lb) underslung crane with 11m (36 ft) bridge that lifted the glass out of and into the building, home of Columbia Pictures. The crane picked up and dropped off panels on a boarded platform. The main contractor Portal used the crane for six weeks.

A second monorail fitted with 500kg (1,100 lb) chain hoist transferred panels from this platform to an overhanging cantilever, and then lowered and raised them to road level.

Mounting the crane on scaffolding was not a problem, according to director Derrick Simpson. Technical Cranes added the total weight of crane, load, and a safety margin, and divided it over supports spread out over 1m centres. It simply gave the scaffolding contractor the total crane loading so that it could develop suitable supports.

Installing the crane was more complicated. It took two weeks to install the two hoists. “It was an awkward job,” Simpson said.

First, Technical Cranes installed a 350kg-capacity winch on one of the final support point of the crane. The winch lifted up the crane’s end carriages and the main bridge beam. The beam was specially made in three 200 kg (440 lb) pieces that were bolted together at splice joints. The team moved the pieces below final position with a transfer buggy. There, on a boarded-out scaffolding platform, they assembled the crane.

In the meantime, end carriage track sections that were lighter (50kg) were lifted into place using rope hoists.
The long travel measured 12m. The girders attached to
the scaffolding with special steel attachments called Lindapters made by Tyco.

Then the team built clamps on the end carriage
tracks and hoisted the bridge up into position using
chain blocks. Once the crane was installed and commissioned, scaffolders removed the platform to
reveal the atrium below.

Both cranes were fitted with Itowa radio remote controls: “We couldn’t have pendants dangling around up there,” Simpson said. Technical Cranes is the Itowa UK distributor.