These photographs from the Second World War come to us from Tony Groucutt of Penn, and are taken from a rather battered booklet that once belonged to his father Norman. The booklet is called Operation Thompson and it was produced by John Thompson Water Tube Boilers Limited of Wolverhampton, to tell the story of their production of landing craft in 1944.
Norman Groucutt worked for John Thompson for around 15 years, before he left the firm in 1951 or ’52. He was a senior fitter, in charge of a number of men, and worked on the construction of 36 landing craft for the Admiralty.
Thompsons received a letter from the Admiralty on 7th April, 1944, enquiring whether they would undertake the order. At that time Britain’s shipbuilding capacity was at full stretch, so alternatives had to be sought to supply the armed forces with transport so desperately needed. This is why a firm of boilermakers in Wolverhampton became shipbuilders, although the company did have many years’ experience in building boilers for shipping.
Thompsons were given the go-ahead on 22nd April and senior management at the company had a meeting at the Admiralty on 27th April, when they were first shown plans. It was decided that the whole of the John Thompson organisation would be given over to building the landing craft.
This was just 10 days before D-Day, so clearly the landing craft were not intended for the Normandy invasion. They were probably for some amphibious assault planned for the following year, perhaps Operation Zipper, the invasion of Malaya pencilled in for late August 1945.
The landing craft made by Thompsons were to be the LCM(7) model. The letters stood for Landing Craft Mechanized, meaning that they carried vehicles. They were 60’ long, with a draught at full load of 3’ 9”, and were powered by two diesel engines.
Construction of the craft was broken down into sections for prefabrication and then assembly in the La Mont Shop.
To enable this a separate drawing office was set up to work only on the plans of the landing craft and a scale model at 1.5” to 1’ was made in tinplate, showing the internal construction, all angles, channels and flats, plating for the bottom, sides, decks and bulkheads.
To meet the Admiralty programme six craft were to be under construction at the same time and so six jigs were built on which the craft were built. They were made so that they could be easily removed from under the craft when the hull was completed and ready for loading onto a road wagon.
The first bottom plates were laid down on 15th July, 1944 and work progressed rapidly.
One of our pictures shows a partially completed hold, looking from the prow to the stern, with port and starboard longitudinal bulkheads, the forward engine room watertight bulkhead and the prow nose with hinges.
At the forward end of the hold was the hinged prow door which could be lowered and raised as necessary to allow tanks and vehicles to be embarked or disembarked.
The craft could carry a 30-ton tank or several jeeps or small utility vans.
Along each side of the hold were three tanks. The forward tanks port and starboard were buoyancy compartments and were always empty but the other two tanks on each side were used to carrying fresh water. They had a special coating on the inside to preserve the freshness of the drinking water and had a combined capacity of 3,000 gallons, around 14 tons.
Below the hold deck were three ballast tanks and sea water could be pumped into these to give the craft stability when she was sailing unladen. These tanks held 5,800 gallons, around 26 tons.
After a series of preliminary trials the Admiralty discovered that the prow door as originally designed was too short to give an easy run off the hold deck onto the landing beach. A longer door had to be built but the weight of the new door had to be similar to that of the old door so an open construction was settled on.
The hull was made of steel plates 1/8” thick, except the bottom plates, which were 3/16” thick. All joints were butted together and electric welded on both sides.
The craft were prefabricated in various parts of the Thompson works. The sections were: Longitudinal girders and transverse beams under hold deck; the longitudinal bulkheads port and starboard, complete with longitudinal frames, ships sides and deck – these were the largest prefabricated sections, being 32’ long by 8’ high and 21” thick; engine room girders and transverse beams, complete with forward engine room watertight bulkhead; rear buoyancy compartment, complete with deck and aft engine room watertight bulkhead; and prow doors.
The construction sequence was as follows: The ship’s bottom plates were laid down on the jigs and tack welded. Then the prefabricated longitudinal girder assembly under the hold deck was placed in position and tack welded to the bottom plates. The prefabricated port and starboard longitudinal bulkheads were then put in position and tack welded to the bottom plates and the longitudinal girders. The engine room girders with the forward engine room watertight bulkheads were put in position and tack welded to the bottom. The rear buoyancy compartment was then put in place and tack welded to the bottom. When this was done, full welding started on all parts, special care being taken to avoid any buckling of the plates.
While the welding was being done the lower part of the craft, the engine room casing top, the remaining ship sides and decks and the transom corners were offered up, tack welded and finally full welded into place.
To make sure the prow door was a good fit against the forward sloping part of the longitudinal bulkhead, a special jig was made. The female half of the prow door hinges were then riveted to a special nose piece at the forward end of the hold and welded. Last, the hold deck plates were fitted and welded up.
Each craft had 11 watertight compartments – nine tanks forward of the engine room, the engine room itself and the rear buoyancy compartment. All these were tested with an air pressure of 1.5lbs per square inch, with all the joints wiped with soapy water to show up any pinholes, and by afterwards filling with water.
The construction was under the supervision of a representative of the Warship Production Superintendent, who was in continual attendance at the Wolverhampton works and witnessed all tests.
Many of the welders who worked on the craft were women.
The landing craft had to be fitted out as well and several squads of fitters worked at the same time on the craft in order to meet the Admiralty’s schedule. We shall look at the fitting out of the landing craft in next week’s edition, along with their launch and sea trials.
One of the pictures we have reprinted is entitled the “JT Regular Crew”. Norman Groucutt stands on the far left of the back row, but Tony cannot name any of the other men. Do readers recognise anyone?