Engineering:Clayton RNLI tractor

Short description: RNLI Amphibious launch tractor

Clayton RNLI tractor
File:The RFC on the Western Front, 1914-1918, Q 12105 (cropped).jpg Clayton Chain-rail tractor in World War I
Manufacturer	Clayton & Shuttleworth
Production	18 (1921–1927)
Weight	3 tonnes
Propulsion	Tracks with 14" track pads
Engine model	Clayton 35-hp
Gross power	35 hp (26 kW)
Drawbar pull	4,500 lb (2,000 kg)
Speed	6 mph (9.7 km/h)
Preceded by	none
Succeeded by	Four Wheel Drive Lorry Company (FWD)

The Clayton RNLI tractor was a continuous track amphibious launch tractor, specifically adapted for the Royal National Lifeboat Institution (RNLI), to launch and recover carriage mounted lifeboats, from beach-launched lifeboat stations.

A total of 18 tractors were constructed by Clayton & Shuttleworth of Stamp End Works, Lincoln, between 1921 and 1927. A further three were never completed.

History

Following the end of World War I, the RNLI turned its attentions to making it easier to launch shore based lifeboats. The use of horses for farming was in decline, and it was becoming increasingly difficult, and more costly, to find a team of horses and men to help launch the lifeboat, causing unacceptable delays.

At a meeting of the RNLI committee of management in January 1920, it was decided to trial a caterpillar tractor, of a type which had proven itself during World War I. Taking advice from Mr F. A. Standen of St Ives, Cambridgeshire, a name now synonymous with agricultural machinery, a 35-hp Clayton Chain-rail tractor was chosen for evaluation.

Five days of trials commenced on Friday 26 March 1920, taking place at Hunstanton, where a variety of type of beach could be found. The tractor performed above all expectations on the first day. On day two, the tractor had no problems towing a 7-ton 3-cwt load, in the form of a 35 ft (11 m) lifeboat and carriage, at its top speed of 6 mph (9.7 km/h), over the sandy beach. However, difficulties were encountered on day three whilst attempting to traverse the sand dunes, resolved following the fitting of six "spuds" (grouser) to each of the tracks.

Things didn't quite go to plan on day four, as the 'un-marinised' tractor unit became waterlogged, after the flywheel covered the engine in seawater, during an attempted launch. As the tide receded some hours later, the tractor was drawn to higher ground by some 70–80 people, where repairs took place. Tractors would be made "seaworthy" with only a few modifications, the magneto and carburettor enclosed in a water-tight compartment, water-tight spark-plug terminals, a splash guard for the flywheel, and the exhaust pipe protruding the bonnet.

Final day trials took place at on the shingle shore at Heacham, proving the expected result that the unit was not suited to such terrain, requiring further investigation for a tractor suited to those conditions and stations.

Following these "successful" trials, the RNLI placed an order for 20 tractors with Clayton & Shuttleworth. The first tractor (T1) was trialled on 23 February 1921 at St Ives; the now waterproof plug terminals giving no problems, and tests in the River Ouse successfully submerged the magneto box to a depth of 4 ft (1.2 m).

A second unit (T2), fitted with tracks with rubber pads, was easily drawn across London from the Poplar storage facility to the RNLI Annual General Meeting at Central Hall, Westminster, where it was inspected by the then Prince of Wales. However, later trials at Template:Lbs still proved unsatisfactory, prompting further development work on track design.

On 11 February 1923, the Template:Lbs lifeboat was launched twice, to the steam trawler Dinorah. It was estimated that the use of the tractor saved at least three hours of launch time. Just 15 days later, the Template:Lbs lifeboat was drawn 1.5 mi (2.4 km) along the shore by the tractor, when the water in the harbour was too low to launch.

Just 18 Clayton tractors were completed for the RNLI. The company of Clayton & Shuttleworth failed in 1928, being taken over by Marshall, Sons & Co. of Gainsborough. However, no further orders were placed. In 1927, the RNLI had placed an order for the next four tractors, a much more powerful unit, with the Four Wheel Drive Lorry Company (FWD) of Slough.

At this time, no examples of the Clayton RNLI tractor are known to survive.

Clayton RNLI tractor fleet

Op. No.	Reg No.	Built	In service	Station	Comments
T1	TC 648	1921	1921	Template:Lbs
			1921	Template:Lbs
			1922–1925	Template:Lbs
			1925–1927	Depot
T2	AH 5933	1921	1921	Template:Lbs
			1921	Template:Lbs
			1922	Template:Lbs
			1922	Template:Lbs
			1924–1930	Template:Lbs
			1930–1938	Depot
T3	MA 6793	1921	1921–1928	Template:Lbs
			1928–1931	Depot
			1931–1938	Template:Lbs
			1938–1939	Cromer No. 2
T4	XA 9192	1923	1923–1931	Template:Lbs
			1931	Template:Lbs
			1931–1933	Template:Lbs
			1933–1938	Template:Lbs
			1939–1950	Template:Lbs
			1950–1951	Template:Lbs
			1951–1953	Depot
T5	IJ 3424	1921	1922–1930	Template:Lbs
			1930–1932	Depot
			1932–1944	Template:Lbs
			1944–1947	Aberdeen No.2
			1947	Template:Lbs
			1947–1950	Template:Lbs
			1950–1951	Template:Lbs (storage)
			1951–1954	Template:Lbs
			1954–1955	Depot
T6	DM 3318	1921	1921–1938	Template:Lbs
T7	AF 4215	1921	1921–1923	Template:Lbs
			1924–1932	Template:Lbs
			1932–1938	Reserve
			1938	Cromer No.2
			1938–1950	Reserve
T8	AF 4256	1921	1921–1923	Template:Lbs
			1923–1925	Depot
			1925–1938	Aberdeen No.2
T9	BE 9914	1922	1922–1931	Template:Lbs
			1931–1937	Template:Lbs
			1937–1939	Depot
T10	AH 9213	1923	1923–1935	Template:Lbs
			1936–1947	Montrose No.2
			1947–1949	Depot
T11	BT 4414	1921	1921–1922	Template:Lbs
			1922–1923	Template:Lbs
			1923–1930	Reserve
			1930–1937	Template:Lbs
T12	IJ 5658 LLY 75	1924	1924–1933	Template:Lbs
			1933–1937	Template:Lbs
			1937–1938	Template:Lbs
			1938–1940	Template:Lbs
			1941–1944	Template:Lbs
			1944–1946	Depot
			1946–1948	Template:Lbs
			1948–1950	Template:Lbs
			1950–1951	Depot
			1951–1953	Template:Lbs
			1953–1955	Depot
T13	Number not used
T14	XW 2075	1925	1925–1932	Template:Lbs
			1932–1933	Depot
			1933–1946	Template:Lbs
			1946–1947	Depot
			1947–1950	Montrose No.2
			1952–1954	Template:Lbs (Reserve)
			1954–1955	Template:Lbs
T15	FU 4892	1925	1925–1932	Template:Lbs
			1933–1949	Template:Lbs
			1949–1950	Template:Lbs
T16	YW 3377	1926	1927–1929	Template:Lbs
			1930–1932	Template:Lbs
			1932–1937	Template:Lbs
			1937–1940	Template:Lbs
			1940–1942	Template:Lbs
			1942–1944	Depot
			1944–1949	Template:Lbs
			1949–1954	Template:Lbs
T17	SR 5361	1926	1926–1936	Montrose No.2
			1936–1941	Depot
T18	PY 7589	1926	1927–1931	Template:Lbs
			1931–1933	Depot
			1933–1938	Template:Lbs
			1938–1939	Aberdeen No.2
			1939–1942	Template:Lbs (Storage)
			1942–1949	Template:Lbs
			1949–1950	Depot
T19	TY 2547	1927	1927–1930	Template:Lbs
			1930–1935	Template:Lbs
			1936–1939	Template:Lbs
			1939–1949	Cromer No.2
			1949–1951	Template:Lbs
T20	Believed not built
T21	Believed not built
T22	Believed not built

See also

• New Holland TC45 launch tractor
• Talus MB-764 launch tractor
• Talus MB-H launch tractor
• Talus MB-4H launch tractor
• Talus Atlantic 85 DO-DO launch carriage
• Fowler Challenger III amphibious tractor