The Leyland Tiger Cub (coded as PSUC1) was a lightweight underfloor-engined chassis built by Leyland Motors between 1951 and 1970, most as 44-45 seat buses, with a smaller number as coaches.
The standard bodied dimensions were 30 ft (9.1 m) long by 8 ft (2.4 m) wide, the UK maximum at launch in 1952.
It was named when a lighter-weight chassis was introduced in 1952 as a modification to the older Leyland Royal Tiger (type PSU1), which was regarded by certain influential customers, especially in the BET group of privately managed bus companies, as overweight, over-specified and too expensive, those who were operating it were also finding vacuum-servo versions under-braked.
It was powered initially by a Leyland O350H 91bhp 5.76-litre diesel engine, a horizontal version of the engine fitted to the Comet 90. It had a newly designed lightweight high straight frame with a vertical radiator set just behind the front axle. The launch transmission was the same four-speed constant mesh unit which had been used in the Tiger PS1, Titan PD1 and their export equivalents. There was a choice of either a single-speed or two-speed rear axle, both of spiral-bevel form and derived from the Comet 90 design, the latter using an electrically actuated Eaton driving head in a Leyland casing. Wheels were of the 8-stud type and diaphragm-type air braking was standard. This was the first time Leyland had offered a bus chassis without another braking option, whilst vacuum or vacuum-hydraulic brakes were still standard across most of the UK bus and coach industry.
Prototypes - two chassis, three bodies
The prototypes were bodied by Saunders-Roe (SARO) of Anglesey as 44-seat buses and were chassis 515176 (OTC738) which was a Leyland demonstrator, working initially for Midland Red (BMMO) in an evaluation trial against its own LA lightweight prototype OHA977, and 520003 which was shown on the Leyland stand at the 1952 Commercial Motor Show in the livery of Ribble Motor Services. At the show it was announced that the BET group would place a launch order for 500 of the new chassis to be bodied in 1953 and 1954. The bodied Tiger Cub weighed around two tons less than an equivalent Royal Tiger, with commensurate savings in fuel.
After the show the SARO body was removed from 520003. It was then fitted on a production chassis which became Ribble 408 (ERN776). It was to be the first of many Ribble Tiger Cubs, whilst Midland Red never purchased new examples of the type. In 1952 these two operators had the largest fleets of underfloor-engined buses within BET, BMMO operating over 450 of their own S1-12 models and Ribble having examples of Sentinel SB40, STC4, STC6, Leyland-MCW Olympic and Leyland Royal Tiger. Ribble were also Leyland's 'home' operator.
After the show body was removed, chassis 520003 was updated to production specification and sent to Walter Alexander Coachbuilders of Stirling where it was fitted with a B45F body and registered EWG240, it served as a demonstrator until 1956 when it was sold to Stark's Motor Services of Dunbar, who operated it until 1967 when it was exported to the Londonderry & Loch Swilly Railway Company of Ireland. Many later Tiger Cubs were rebodied, generally after accident damage, but occasionally when a coach operator wanted a more up to date appearance. The last such rebodying was done for Western Welsh by Willowbrook in 1971.
The initial production model was type PSUC1/1T, with the two-speed axle as standard. Omission of this was a no-cost option, in which case the T-suffix was omitted.
In 1953 two variants emerged. For coaching duties type PSUC1/2T had a dropped-frame extension at the rear for a luggage boot and a higher-ratio rear axle for a higher road speed. Among the first customers were Scout of Preston, an independent coach operator who competed with Ribble on Lancashire-London express services. They had the first five Duple Elizabethan-bodied coaches in early 1954.
In 1952 Leyland had bought into Self-Changing Gears Ltd, Coventry. This company owned the patents for the preselective type of epicyclic gearbox which Leyland had fitted to the RTL & RTW Titans it sold to London Transport. It was working on a new type of direct-acting epicyclic gearbox at the time of the Leyland takeover. Leyland announced this product in 1953 as the Pneumocyclic; the first two demonstrators were Leyland Titan NTF9 and Tiger Cub PTE592. The Tiger Cub demonstrated to London Transport during 1953/4 alongside an AEC Monocoach and a Bristol LS6G.
This version of chassis had a four speed transmission with direct-air pedestal shift and entered production as type PSUC1/3 from 1955. Also in that year two versions for 7 ft 6 in (2.29 m) wide coachwork were announced; these differed from the previous types in having narrower axles. These were type PSUC1/4 with Pneumocyclic gearbox and PSUC1/5 with constant mesh.
Two revisions to specification which were not accompanied by a change in specification number were from 1957 when an Albion five-speed constant-mesh gearbox became an option for manual-transmission chassis and from 1958 when the 105bhp 6.15 litre O375H engine became optional across the range.
Although conceived for the home market, export versions were soon introduced, these were the OPSUC1, with heavier duty tyres and suspension, and the LOPSUC1, which also had left hand drive, suffixes and options as for home market models.
In 1962 the power unit became the 125 bhp 6.75-litre O400H and the type codes were revised, to PSUC1/11, PSUC1/12T and PSUC1/13. These were respectively manual bus, manual coach and pneumocyclic bus versions. The narrow models were discontinued. At this time the manual transmission options changed to Leyland 4-speed synchromesh or Albion 5-speed constant mesh. Production continued until 1969.
The last Tiger Cub of all was bodied by Fowler of Leyland as a 44-seat bus and entered service with their parent company J Fishwick & Sons Ltd, registered VTD441H in January 1970. It is preserved.
Customers and coachwork
The BET group were the largest purchasers in England and Wales. Of their subidiaries, Western Welsh Omnibus Co with a fleet of 271 had the most. In Scotland the largest customer was Walter Alexander and Sons who took 200 between 1955 and 1964. The largest municipal fleet was that of Edinburgh Corporation, who took 100 from 1959 to 1961, these were also the largest fleet of pneumocyclic Tiger Cubs. UTA in Northern Ireland and JMT on Jersey were the major customers for the narrow manual version, which Jersey initially took with shorter than standard rear overhang, reducing length to around 27 ft (8.2 m). West Bromwich Corporation took ten of the narrow pneumocyclic version, the only ones built (?). Independents took Tiger Cubs as buses, coaches and dual-purpose vehicles, but as with the municipal Market, the Tiger Cub was not as strong a seller as the AEC Reliance.
Bodies were produced on UK Tiger Cubs by Alexander, Beadle, Burlingham, Crossley, Duple, Duple (Midland), East Lancashire, Fowler, Harrington, Marshall, Massey, Metro-Cammell, Northern Counties, Park Royal, Pennine, Plaxton, Roe, SARO, UTA, Weymann, Willowbroook and Yeates.
Major export markets for the Tiger Cub were Denmark, The Netherlands, Jamaica, and Ceylon (Sri Lanka). Leyland often sold export batches with Metro-Cammell Weymann group (MCW) bodywork, but bodies were also produced by other UK firms and by local coachbuilders.
The Tiger Cub was very much the product of its straitened times, and throughout its production life faced stiff competition from the AEC Reliance MU (1953–75). This had a larger capacity engine (and a vacuum brake option until 1966). The AEC version of the semi-automatic gearbox (Monocontrol) came as standard with a faster-engaging electro-pneumatic control. From 1961 when longer single decks were allowed domestic sales of the Tiger Cub began to tail off, and by 1969 the model could be considered replaced in the British Leyland catalogue by the similarly powered Bristol LH. BET depreciated buses and coaches on the basis of a 12 year life, so most of its examples were sold quite early, SBG, like many municipals, wrote its vehicles down over 15-years, with the result that most had disappeared from service in the middle 1970s. A number, both buses and coaches, survive into preservation. Overall, global sales were not as great as for the heavier Royal Tiger Worldmaster or later Leopard models but it kept Leyland in contention for home market single deckers during the 1950s.