Tilling-Stevens

Tilling-Stevens

Company type	Private
Industry	Automotive
Founded	1897
Founder	William Arthur Stevens
Defunct	1950
Fate	Acquired by Rootes Group
Headquarters	Maidstone , United Kingdom
Products	Buses, commercial vehicles, petrol-electric propulsion systems
Parent	Rootes Group (from 1950)

Tilling-Stevens was a British company producing buses and commercial vehicles, headquartered in Maidstone, Kent. Established in 1897, the firm specialized in petrol-electric propulsion systems and remained independent until its acquisition by the Rootes Group in 1950.

W A Stevens of Maidstone

The company W.A. Stevens was founded in Maidstone in 1897 by William Arthur Stevens. By 1906, it had developed its initial petrol-electric vehicle, utilizing designs patented by Percival (Percy) Frost-Smith. The vehicle's powertrain consisted of a petrol engine driving an electrical generator, which in turn supplied electricity to a traction motor that propelled the rear wheels. W.A. Stevens also secured a patent (GB190820210) for a method to convert standard petrol buses into battery-electric or petrol-electric vehicles.

Percy Frost-Smith

Percival Harry Frost-Smith served as Managing Director of Tilling-Stevens Ltd circa 1915–1916 and was responsible for several patents enhancing motor vehicle technology between 1908 and 1918, including:

• Collaborating with William Arthur Stevens on a Worm drive for vehicles
• Partnering with Francis Edwin Brown on Improvements in and relating to Worm Drive for Mechanically Propelled Vehicles
• Working with Victor Snow Robinson on Improvements in and connected with the Electric Lighting of Vehicles
• Alongside Tilling-Stevens Ltd, developing an Improved Means of Control for Petrol Electric Vehicles

Francis Edwin Brown was the son of David Brown from David Brown Ltd.

Hallford-Stevens and Dennis-Stevens

The petrol-electric drivetrain was installed on chassis manufactured by J & E Hall of Dartford, marketed under the name "Hallford-Stevens." Additionally, transmissions were supplied to Dennis Bros of Guildford, resulting in "Dennis-Stevens" branded vehicles.

Tilling-Stevens

Following an agreement with prominent bus operator Thomas Tilling, Tilling-Stevens vehicles were produced. Their reputation for ease of operation and sturdy build led to broad usage both within the UK and internationally. Drivers preferred the straightforward petrol-electric transmission over traditional crash gearboxes, particularly before synchromesh gearboxes became common.

During World War I, Tilling-Stevens Motors Ltd encountered difficulties as the military rejected their petrol-electric chassis for deployment in France due to exposed electrical components mounted low on the frame. After the war, improvements in gearbox technology combined with enhanced driver training shifted preference toward conventional petrol or diesel engines paired with gearboxes, reducing demand for petrol-electric systems. By the 1930s, Tilling-Stevens had transitioned to producing chassis with standard powertrains.

In 1927, eighteen prisoner transport vehicles were constructed on Tilling-Stevens chassis rated at a gross weight of 2500 kg, along with an emergency service model.

Tilling-Stevens separated from Thomas Tilling in 1930, becoming T S Motors Ltd (TSM) in 1932, before reverting to the Tilling-Stevens name in 1937 prior to World War II.

After World War II, Tilling-Stevens continued manufacturing buses and fulfilled a significant export contract during 1947/48 supplying Hong Kong operators China Motor Bus (108 units) and Kowloon Motor Bus (50 units).

In 1950, Rootes Group acquired Tilling-Stevens; notably, a three-cylinder two-stroke engine developed by TS found extensive use in Rootes’ Commer lorries.

Trolleybuses

Tilling-Stevens manufactured trolleybuses, initially supplying Wolverhampton Corporation, which replaced trams with trolleybuses on a specific route. They modified the hybrid TS6 model by integrating electrical equipment from BTH based in Bath, Somerset and fitted bodies constructed by Christopher Dodson; the first six units began operation in 1923. Following this, additional orders were placed by Halifax Corporation. In 1924, the general manager of the Teesside Railless Traction Board designed a trolleybus chassis produced by Tilling-Stevens (known as PERC1), which could operate using a petrol engine to power both the dynamo and traction motor or draw energy from overhead wires.

After obtaining the rights to the Teesside design due to international interest, domestic production ceased after 1927. Following their separation from Thomas Tilling, a single new chassis was exhibited at the 1930 Scottish Motor Show and sold exclusively to Turin, Italy.

Goods vehicles

Tilling-Stevens built goods vehicle chassis featuring either petrol-electric or traditional transmissions, manufacturing numerous trucks during World War I. Their signature cast aluminium radiators were embossed with "Tilling-Stevens" alongside either "Petrol-Electric" or "Maidstone."

Following the war, with only minor updates to their products, the company concentrated more on bus production. To broaden their lineup and make use of Vulcan petrol engines, they acquired Vulcan Trucks based in Southport, Lancashire in 1938, consolidating manufacturing operations at Maidstone.

While competitors introduced simpler mechanical transmissions, Tilling-Stevens focused on specialized markets where their electric transmission offered distinct benefits—such as early fire engines equipped with turntable ladders powered by electric motors and fitted with arc lamps.

During the 1930s, lorry designs evolved from large cast radiators to slimmer aluminium casings and eventually to steel pressed bonnets featuring a small diamond-shaped "TSM" badge.

As World War II approached, they specialized in producing searchlight trucks, a niche for which they became particularly noted.

Rootes Group

The company was acquired by Rootes Group in 1950. Complete vehicle manufacturing ended by 1953 as Rootes prioritized its own heavier truck brands. However, the Maidstone facility continued producing light commercial engines—most notably the renowned Commer TS3 two-stroke diesel engine originally intended for Tilling-Stevens in 1954—and vehicle bodies until its closure during the 1970s, several years after Rootes itself was taken over by Chrysler.

Factory

Situated on St Peter's Street in Maidstone, the Tilling-Stevens factory was constructed during the 1920s following the Daylight architectural style. As of 2012, these buildings remain intact and were granted Grade II Listed status in July 2011, recognized as one of the rare surviving examples of this architectural style largely preserved in its original form.

Petrol Electric Engines and Legacy

Tilling-Stevens were pioneers in petrol-electric bus technology, employing electric transmissions instead of conventional mechanical gearboxes. Unlike modern hybrid vehicles, these buses did not incorporate battery storage; instead, a petrol engine powered a dynamo and electric motor that functioned as a gearbox alternative.

Because the engine operated continuously and had to drive a heavy motor/dynamo assembly, fuel consumption was less efficient compared to mechanical transmission systems. The development of reliable and user-friendly mechanical gearboxes eventually rendered the petrol-electric system obsolete. Furthermore, its rudimentary electrical controls limited performance before advances in modern electronics emerged. Despite this, contemporary hybrid vehicles such as the Toyota Prius exemplify strategic efforts to reduce carbon emissions and address global warming concerns.

Many Tilling-Stevens petrol-electric vehicles enjoyed prolonged secondary use as mobile caravans or fairground transporters where their electrical generation capabilities supported auxiliary functions beyond propulsion. Some chassis were converted into generator trailers at fairs, preserving key components and enabling restoration projects that contribute to historical vehicle conservation.

Driving a Petrol-Electric

In early petrol-electric vehicles, the large dynamo generator was permanently linked to the petrol engine. The control setup typically featured a throttle pedal with a spring return, a hand-operated adjustable latch to set idle speed, a brake pedal, steering mechanism, and two levers mounted on the steering column. One of these levers functioned as a three-position switch to select forward, neutral, or reverse, while the other adjusted a wiper across high-current wire-wound resistors. This resistor control simulated gear changes by varying the fields of the motor and dynamo. Properly setting the minimum idle speed was essential to prevent excessive load or unintended movement during direction changes. Before choosing forward or reverse, the resistance lever was positioned to deliver maximum torque. Smooth acceleration, free from the jerking typical of gearboxes, was achieved by releasing the handbrake and gradually pressing the throttle. Increasing speed involved moving the resistance lever accordingly. To come to a halt, the driver would ease off the throttle, reduce resistance, apply the brakes, shift the direction lever to neutral, and then engage the handbrake.

It is important to note that unlike mechanical gearboxes, these systems lacked engine braking; stopping power depended entirely on mechanical brakes usually located on the rear axle.

Engine controls were quite basic—generally limited to a choke lever and an ignition timing advance/retard for starting the hand-cranked engine. Models equipped with magneto ignition included a simple switch to cut off engine operation.

See also

• Leyland L60