By 1933, John I Thornycroft & Co Ltd had been well-established as a major commercial and military vehicle manufacturer for many years. Products from the firm’s Basingstoke factory served in home and export markets, earning a reputation for reliability and competence. The following timeline covers Thornycroft’s lorry activities from 1933 to 1939.
Thornycroft offered four-wheel and RSW lorries with load capacities ranging from 2 tons to 12 tons (2,032kg to 12,192kg). In addition, new capacity options included 2.5, 3.5, 7.5 and 10 tons (2,540, 3,556, 7,620 and 10,160kg). Type names were carried over from 1932, and new ones included the four-wheel Bulldog (2.5 tons/2,540kg), Beauty (3.5 tons/3,556kg), and the short-lived Jumbo RSW (11 tons to 12 tons/11,176kg to 12,192kg). The Taurus four-wheeler (6 tons to 6.75 tons/6,096kg to 6,858kg) had a bonnet projecting well forward of the front axle, known as a ‘snout’, giving the required weight distribution and increased accessibility.
A Speedy fire engine for use in Lymington, Hampshire.
Diesel engines, introduced to commercial vehicles about six years previously and often referred to as oil engines, had gained acceptance. In May 1933, 12 diesel engine manufacturers, including Thornycroft, offered diesel engines on the British market for commercial vehicles. Eleven of these firms were British and one was German, most of them were vehicle manufacturers while the others were engine manufacturers.
After entering the diesel field late, Thornycroft offered diesel options for its heavy four-wheelers, namely the Taurus (6 tons to 6.75 tons/6,096kg to 6,858kg) and Iron Duke (7 tons/7,112kg), as well as for its larger RSWs, the Amazon (6 tons/6,096kg), Dreadnought (10 tons to 11 tons/10,160kg to 11,176kg), Jumbo (11 tons to 12 tons/11,176kg to 12,192kg) and Mastiff (7.5 tons/7,620kg). Thornycroft produced two diesel engines, both announced in 1932, the four-cylinder 7,559cc CIND4 rated at 82bhp@1,800rpm, and the 11,339cc six-cylinder CIND6 giving 123bhp, also at 1,800rpm. Both these diesels had indirect injection, so that fuel was injected into a separate chamber in the cylinder head, each chamber being connected to its cylinder via a passage.
This Taurus works for a Rugby-based building materials firm.
Diesel engines were in the minority compared to petrol engines and, for 1933, Thornycroft’s range of petrol engines included three ‘sixes’, the 4,259cc SC6 giving 75bhp, the 7,749cc AC6 (99bhp) and the vast 133hp NED6 of 11,330cc – Thornycroft’s most powerful lorry engine at that time. Four-cylinder petrol engines comprised the ageing MB4 giving a leisurely 60bhp from 6,976cc, and, also inherited from previous years, the 3,625cc FB4 whose 40bhp put it way behind the 55bhp from the newly-introduced GD4 of the same capacity.
At Thornycroft’s AGM in November, Sir John E Thornycroft, KBE, announced that the number of vehicles exported had been falling for several years, and had fallen to 12 per cent of the 1929 figure. The firm made a loss of no less than £84,940 for the financial year. Sir John said that depressed trade and uncertainty about new legislation had adversely affected the motor vehicle business at home, but pointed out that there had been a revival now that the effects of legislation had been made clear.
A Stag RSW tanker
Thornycroft’s range of lorries for this year covered load capacities from 2 tons to 12.5 tons (2,032kg to 12,700kg), little changed from the previous year (2 tons to 12 tons/2,032kg to 12,192kg). This was achieved with the following lorries
A Trusty OE/DC6 normal control rolling chassis powered by a six-cylinder DC6 diesel.
The diesel version of the 7.5 ton to 8 ton (7,620kg to 8,128kg) Trusty was fitted with Thornycroft’s newly introduced 5,258cc DC4 diesel engine, a four-cylinder unit giving 65bhp@2,200rpm. This was an indirect injection engine, in which fuel was injected into a short cylindrical chamber in the cylinder head, connected by a tangential passage to the cylinder, for causing swirl to promote good mixing of air and fuel. A Dorman diesel engine was bought in to power the new 4 ton Bullfinch four-wheeler as Thornycroft did not produce a diesel matching Dorman’s relatively small 3,055cc four-cylinder 4DS (48bhp@2,500rpm). Also, Dorman’s 4,148cc four-cylinder 4JUR diesel (58bhp@2,000rpm ) was specified for the 4 ton (4,064kg) Steadfast four-wheeler.
Tom Thornycroft, a director of John I Thornycroft Ltd, left the firm while working as general manager of the Basingstoke works. He was, at the time, chairman of the Research and Standardisation Committee of the Institute of Automobile Engineers.
This Handy coal lorry is displayed at the Milestones Living History Museum.
Photo Nick Corrie
Thornycroft made a loss of £51,110 after providing for depreciation, etc, the year ending 31 July 1934. Although large, this figure was an improvement over the previous year’s loss of £84,940. When debenture interest, director’s fees, etc were included, the total deficit was £66,980. Fortunately, this loss could be covered by transferring £66,000 from the reserve account and, after transfer fees, the year’s deficit was £2,574. The firm increased motor vehicle sales by 64 per cent compared with 1933, and the management of the motor vehicle side had been reorganised.
Thornycroft continued producing the four-wheel range introduced the previous year, with additional Trusty options. However, the Amazon and Tartar RSWs were no longer listed for the British market, leaving only the forward-control Stag (10 tons to 12.5 tons/10,160kg to 12,700kg) to represent the RSW sector, offered, as previously, with the 7,749cc 104bhp AC6 petrol engine or the vast 11,339cc 123bhp CIND6 indirect injection diesel. Both these were six-cylinder engines. Although not listed for sale in the UK, Tartar and Amazon RSWs were exported.
The range of articulated lorries continued as for 1934, with the addition of the 12 ton (12,192kg) Amazon artic offered with petrol and indirect injection diesel engines, the former being the six-cylinder AC6 engine used in the Stag and the latter the four-cylinder CIND4 giving 82bhp.
This handsome Amazon, devoid of livery, may be for overseas use.
During the Summer, the 3 ton (3,048kg) Bulldog petrol-engined chassis was cleared for a 33.3 per cent overload, transforming it into a 4 tonner (4,064kg). Also, the firm introduced the Dandy 3 tonner (3,048kg), closely following the successful 2 ton (2,032kg) Handy in design, with stronger axles and springs. As with other Thornycroft lorries, the Dandy was offered in alternative forms; in the Dandy’s case there were four versions, i.e. short and long wheelbase, normal and forward control.
Thornycroft introduced an uprated version of its four-cylinder 65bhp DC4 diesel. The DC4/1, as the new engine was called, gave 85bhp, an increase of no less than 31 per cent. This power increase was all the more impressive for being achieved without an increase in rpm. The engine was governed to 2,200rpm, however it was capable of giving more power at increased rpm, and had been run on test for long periods at 100bhp. Modifications included the Ricardo arrangement of indirect injection in which fuel was injected into a spherical chamber in the cylinder head, one chamber per cylinder, connected by a tangential passage to the space above the piston – this Ricardo system replaced the system of indirect injection (possibly of Thornycroft design), which used a cylindrical chamber in the cylinder head.
Also, an impressive 25 per cent power increase from the four-cylinder petrol FB4 engine was obtained, rising from 40bhp@1,800rpm to 50bhp@2,300rpm, by means of a Ricardo cylinder head giving a higher CR (5.2 to 1), and revisions to port, valve and camshaft design. These mods improved breathing, and probably thermal efficiency. The uprated engine was redesignated FB4/1 and was remarkably free-revving for a commercial vehicle engine of its time, reaching a heady 3,350rpm when taken up to 34mph (55kph) in third gear during a road test of a four-wheel Dandy 3 tonner (3,048kg).
J I Thornycroft and Co Ltd reported a continuing poor financial performance, and, for the year ending 31 July 1935 a trading loss of £86,360 was recorded, after providing for depreciation and bad debts, the figure being increased to £102,054 after adding £13,500 of debenture interest, directors’ fees (£1,770), etc, which was worse than the previous year’s loss of £66,980. Transfers from the reserve account and the special reserve account reduced the deficit to £36,037, converting the credit balance of £2,574 in the previous year’s report into a debit of £33,463. The loss arose in connection with the motor vehicle side of the company’s activities.
The diesel-powered Bullfinch 3 tonner (3,048kg) was dropped for 1936 and, instead, the petrol-driven Dandy represented Thornycroft in the 3 ton (3,048kg) four-wheel class.
The Sturdy class name was re-introduced after an absence of two years, as a 4 ton to 5 ton (4,064kg to 5,080kg) petrol-driven four-wheeler. For its other four-wheel contenders, Thornycroft continued with the Handy (2 tons/2,032kg), Bulldog (4 tons/4,064kg), uprated from 3 tons (3,048kg) in 1935, Steadfast (4 tons/4,064kg), Beauty (4.5 tons to 5 tons/4,064kg to 5,080kg), Speedy (4.5 tons to 5 tons/4,064kg to 5,080kg) and Trusty, the latter being available as a 6.75 to 7 tonner (6,858kg to 7,112kg) or an 8 tonner (8,128kg).
The seemingly wasteful duplication of models in the 4 ton to 5 ton (4,064kg to 5,080kg) class was partly offset by the 4 ton (4,064kg) Steadfast which was the only diesel option in the load class, and the Speedy, which offered a performance advantage thanks to its six-cylinder engine. That Thornycroft recognised the need for rationalisation was, perhaps, evidenced by a pruning of the model range for 1937.
An expanded range of the high capacity Trusty class of four-wheelers was offered with petrol or indirect injection diesel engines, and the 6.75 ton to 7 ton (6,858kg to 7,112kg) versions were powered by the new 99bhp six-cylinder DC6 indirect injection diesel. In due course, this engine was redesignated DC6/1 after uprating to 125bhp@2,200rpm with the Ricardo system of indirect injection applied to its smaller brother, the DC4/1 (see 1935).
The RSW category was represented by the 10 ton to 12.5 ton (10,160kg to 12,700kg) Stag. The Taurus artic was not listed for 1936, resulting in the demise of the Taurus name, and artics comprised the petrol Dandy (4 tons to 5 tons/4,064kg to 5,080kg), petrol Bulldog (5 tons to 6 tons/5,080kg to 6,096kg) and diesel Steadfast (5 tons to 6 tons/5,080kg to 6,096kg).
Commander J W Thornycroft, commercial-vehicle sales manager of the Thornycroft company, reported that exchange values and tariff walls were proving serious obstacles in export markets. He also noted that the export of commercial vehicles from Germany and Italy was being organised on a national basis with substantial government subsidy. He said that if this state of affairs were to continue, then it would be essential for British industry to voluntarily organise itself along similar lines, or the government should step in and take an active interest in the UK obtaining export business, by compulsory rationalisation of the industry or by giving subsidies on export business.
The model range was pruned for this year. There was no longer a 4.5 ton (4,572kg) category and, of the four-wheelers, gone were the Bulldog and Steadfast 4 tonners (4,064kg), as well as the Beauty and Speedy 4.5 to 5 tonners (4,572kg to5,080kg). The four-wheel class was represented by the Handy (2 tons/2,032kg), Dandy (3 tons/3,048kg), Sturdy 4 tonner (4,064kg), Sturdy 5 tonner (5,080kg) and Trusty ranging from 6.25 tons (6,350kg) to 7.75 tons (7,874kg). As usual, there were alternatives within each class name (e.g. forward control, long wheelbase, etc), with the greatest number of alternatives bearing the Trusty name - increased to 24 from the previous year’s eight. The Handy and Dandy options were all powered by the four-cylinder FB4/1 50bhp petrol engine with the Ricardo cylinder head, the ten Sturdy options all had the four-cylinder TC4 60bhp petrol engine, while the Trusty variants used various four and six-cylinder diesel and petrol engines ranging in power from 76bhp to 125bhp.
With the demise of the Stag, no Thornycroft RSWs were offered for 1937 in the UK. However, RSWs were exported, e.g. Amazon.
Petrol-driven Dandy (5 ton/5,080kg) and Sturdy (6 ton to 8 ton/6,096kg to 8,128kg) articulated six-wheelers were listed for the British market, and a diesel-powered Tartar ten-wheeler export ‘special’ was produced for carrying mining equipment. This vehicle had off-road capability. A powerful six-cylinder Trusty tractive unit was introduced in July, available in petrol or diesel form and with a load capacity of 13 tons (13,208kg).
Lorries in the 2 ton to 13 ton (2,032kg to 13,208kg) load range were offered.
The four-wheel range continued as for the previous year, except four of the Trusty options which were dropped. Similarly, RSWs were not listed in the UK, but were available for export (e.g. Amazon). Articulated lorries were represented by the Sturdy 6 tonner (6,096kg) and the 13 ton (13,208kg) Trusty, both carried over from 1937, while vehicles not listed in the UK were exported (e.g. Amazon ten-wheelers). The Dandy 5 tonner (5,080kg) was discontinued for 1938.
For the year ending 31 July, John I Thornycroft and Co., Ltd made a good profit of £160,006 after deducting £13,500 for debenture interest.
The new Dreadnought forward-control RSW 10 tonner (10,160kg) was displayed at the Scottish Show towards the end of the year, as part of Thornycroft’s home market range for 1939. Instead of having, as before, two rear axles, the Dreadnought had two front (steering) axles and one rear axle. Also at the Scottish Show was the new four-wheel Nippy 3 tonner (3,048kg), also intended for sale as part of the 1939 range.
The Dandy 3 tonner (3,048kg) was replaced by the new Nippy of the same capacity, shown at the previous year’s Scottish Show. The Handy 2 tonner (2,032kg) was dropped, and Thornycroft did not replace it with another vehicle in the 2 ton (2,032kg) class. Also, the number of variants available in the Trusty range was pruned. Thus, Thornycroft’s four-wheel range comprised the Nippy (3 tons/3,048kg), Sturdy (4 tons/4,064kg), Sturdy (5 tons/5,080kg) and the Trusty (6.5 tons to 8 tons/6,604kg to 8,128kg).
The twin-steer Dreadnought RSW 10 tonner (10,160kg), displayed at the Scottish Show the previous year, was the sole Thornycroft RSW offered on the British market. This vehicle was powered by a bought-in Dorman NF/5LW 85bhp diesel engine.
WW2 started on 3 September 1939, at 11.15am, when British Prime Minister Neville Chamberlain announced that the UK was at war with Germany. During the six-year conflict, the production capacity of engineering organisations was used to support the war effort. Among other things, Thornycroft produced parts for guns and aero engines, complete guns, exploders for bombs, depth charge throwers, vehicles for military and civilian use including lorries and armoured tracked vehicles etc, and torpedo rudders. Lorries built for civilian operators included Trusty, Nippy, Sturdy and Dreadnought RSW. Due to its lack of success, the Dreadnought did not enter production until after the start of the War, when operators were willing to take any available vehicle. Thus, a small number of Dreadnoughts was built from existing components .between the end of 1939 and early November 1941.
No bonnet extension on this forward-control Trusty indicates a four-cylinder engine.