Registration number 2064
Status Registered
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Details

Function Cargo Vessel
Subfunction Barge
Location Oulton Broad
Vessel type Ferro Concrete Barge
Current use Commercial Activity
Available to hire No
Available for excursions No

Construction

Built in 1944
Hull material Concrete
Rig None
Number of decks 1
Propulsion Towed
Primary engine type None
Boiler type None
Boilermaker None

Dimensions

Length: Overall
84.00 feet (25.62m)

History

CONCRETION is a ferro-concrete barge (FCB) built circa1944 for the Ministry of War Transport to distribute drinking water to Allied forces in the Mulberry Harbour built in Normandy to support the D-Day landings. 

FCBs were subdivided by four reinforced concrete bulkheads to create three large water tanks leaving a small fore peak and after peak to provide the buoyancy to keep the whole vessel afloat when all three tanks were full of fresh water (which is lighter than sea water). They were not powered but had a large rudder and tiller to assist when being towed or manoeuvred.

On deck they were fitted with a large, powered pump with all the necessary valves and pipework to discharge the water into small vessels, or presumably into lorries that could get alongside on the piers of the Mulberry Harbour to fill up with fresh water for the troops.  There was a crude shelter for the crew, which was believed to have been canvas-covered, although no photograph of these vessels in use has been found.  It is presumed they were replenished from the five specially built CHANT- type coastal water tankers which shuttled fresh water across the Channel until D-Day plus forty when it became possible to use captured channel ports.

Vessels built of ferro-concrete only required 20% of the steel needed for conventional construction, and the chalk and coal required for the cement, and the aggregate, were all readily available in wartime Britain to make the concrete. 

Unlike the Shoreham Creteships of WW1, the FCBs were built of a combination of thin pre-cast reinforced concrete panels joined by in situ reinforced concrete ‘beams’ acting as keelson, frames, and deck beams, thus forming a monolithic structure that could be rapidly mass-produced.  Conventional concrete construction in a marine environment demands 75mm of cover over the mild steel reinforcement, giving a minimum thickness of more than 150mm.  However, the FCB’s pre-cast panels are only 50mm thick, yet there are no signs of the reinforcement rusting and ‘blowing’ the concrete, which would normally be the case.  It transpires that the cement used was extra fine and so waterproof that the reinforcing bars are still blue as originally milled, even after the concrete panels had been immersed in sea water for fifty years. 

To speed construction, special spring clips were developed to save on the labour required to wire the reinforcing bars together. These clips remain in perfect condition and were reused in the repairs carried out on the slip. 

CONCRETION therefore demonstrates the considerable ingenuity of her designer who is believed to have been Guy Maunsell, the renowned British Civil Engineer who had designed the Shoreham Creteships of the First World War, and the Navy and Army Sea Forts of the Second.     

The water-carrying FCBs were ‘one-use’ vessels that were largely abandoned after the War.  This one was found adrift off Lowestoft in 1949, salvaged by local fishermen and towed into Lowestoft.  She was eventually bought from the Admiralty Marshall by J E Fletcher Ltd who had a boatyard in Lowestoft’s inner harbour.  Here it was sunk to form a ‘T’ head to their jetty which was for many years used for the maintenance of RNLI lifeboats.

After this yard changed hands around 2005, the FCB was given to the Excelsior Trust who repaired her and gave her a new role as a mooring barge, store and workshop for their historic Lowestoft smack, Excelsior LT472. 

The FCBs were identified by numbers painted on the steel fairlead in the bow, but as no trace of a number remained on this FCB she was renamed CONCRETION.

These vessels were hurriedly designed, built as quickly as possible sometimes indifferently using conscripted labour, while requiring a minimum of imported raw materials.   They successfully served their intended purpose for a few months in 1944 and this one, having been found adrift in the North Sea, was deliberately sunk for fifty-six years in seawater.  She has never been maintained and has only had one slipping in her entire life, yet now she is serving in a new life as a mooring barge, store, and workshop.  

CONCRETION is an amazing testament to wartime Britain’s ability to rapidly design, build, and successfully deploy an ingenious solution to the urgent need for drinking water during the liberating forces assault on Europe from the sea.

- John Wylson, Excelsior Trust, April 2023

  

 

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If you are the owner of this vessel and would like to provide more details or updated information, please contact info@nationalhistoricships.org.uk

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