24th January 2019

Machining the Mast Top Radar Base – HMS Bulwark

Foretract were tasked with the machining of the base for the main radar at the very top of the mast on HMS Bulwark.

The Mast top or as traditionally known as the “crow’s nest” had to be replaced due to corrosion and a newly fabricated unit had been installed.

The base that the radar is mounted to has to be flat and level to within + – 4 minutes of the ships level so that it is working on the same plane as all the other ships systems.

This task was a 2 part process. First a small milling machine was mounted using a specially made mounting plate and the entire pad was machined flat with pockets as required. Once this was completed the actual radar feet pads were bolted to the newly machined base.

The second part of the job was to use a flange facing machine on a special adjustable (for level) mounting plate that allowed the machining of the 4 radar feet pads to within the accuracy required to produce a finish that was within tolerance for level and flatness.

Obviously lifting the equipment to the top of the mast using a mobile crane was a priority and Foretract cooperated with Babcock’s engineers to produce a safe lifting plan.

The whole job including slinging to the mast top and back down again on completion took 3 days.