esthetically and aerodynamically the T51 was a natural development of the T43 and T45 cars that had given Cooper their first two wins. The Coopers continued their practice of building spaceframe chassis that ignored orthodox design thinking in having several curved links and the rear-engine layout meant weight savings and aerodynamic advantages over the front-engined cars, which had to find room for propshafts to the rear wheels. Also the location of the fuel tanks on either side of the cockpit rather than at the rear meant the car handled more consistently with different fuel loads, a vital factor during races which lasted up to three hours. One notable throwback, however, was the car's leaf spring rear suspension, although it used a more modern coil spring and wishbone setup at the front.
Engine & Transmission
The standard F1 T51 was the first Cooper powered by the 2.5-litre 4-cylinder engine which Cooper and Lotus had commissioned Coventry Climax to build specifically for their rear-engined machines. The pioneering nature of this configuration created problems of its own, since there were so few rear-engined production cars from which a gearbox could be sourced. This shortage eventually created a niche in the market which paved the way for Hewland's prominence, but in the meantime many different solutions were tried, with varying degrees of success. The works Coopers were fitted with modified Citroën gearboxes, while Rob Walker's team ran bespoke units from Italian specialist Valerio Colotti, although these proved much more fragile.
In all, eight different engines were used in the back of T51s in championship races, with 2.2- and 1.5-litre Climax engines in addition to the standard 2.5: Scuderia Centro Sud and others used 2.5 and 1.5-litre engines from Maserati; the British Racing Partnership team used F2 powerplants from Borgward; Scuderia Eugenio Castellotti used their own Ferrari-derived 2.5-litre units; and one car used a Ferrari 2-litre engine lifted from a 625LM.
A Historic Season
The T51 had already won the Glover Trophy at Goodwood and the Silverstone International Trophy before it made its first World Championship appearance in the 1959 Monaco Grand Prix, with no less than eight examples entered. The Cooper works team fielded Jack Brabham, Bruce McLaren and Masten Gregory, Stirling Moss and Maurice Trintignant were entered by Rob Walker, two 1.5-litre F2 cars were entered by Equipe Nationale Belge for Lucien Bianchi and Alain de Changy, with Ivor Bueb driving another F2 machine. Only the five 2.5-litre cars qualified, with Stirling Moss in pole position (Cooper's first) and Brabham starting in third place. Jean Behra took the lead at the start, but after his Ferrari developed engine problems after 21 laps the Coopers dominated, with Moss and Brabham running first and second until Moss's transmission gave up the ghost 19 laps from the end. Brabham cruised to his first World Championship win with Trintignant third and McLaren fifth. From Monaco on Cooper's season went from strength to strength, with Brabham leading the championship from start to finish. Brabham took his second win in the British Grand Prix, before Moss took a brace in Portugal and Italy and dominated the non-championship Gold Cup. By the final race at Sebring Cooper already had the Constructors' Championship in the bag, but the Drivers Championship was still up for grabs. Moss needed to beat Brabham and finish second or better to take the title, while Ferrari's Tony Brooks had a mathematical chance but needed both the win and fastest lap. Moss sprinted into the lead from pole position with Brabham in pursuit. After five laps Moss was a commanding ten seconds ahead, before his gearbox gave way again. Brabham led right up to the final lap, when a poor decision on Brabham's part meant he ran out of fuel. He managed to push his car across the line in fourth, but Cooper still won the race as Bruce McLaren became the youngest winner in Formula One history (a record he held until surpassed by Fernando Alonso in 2003), leaving Brabham the Drivers' Champion.
Cooper travelled down to the 1960 Argentine Grand Prix seemingly at the peak of their powers, and Trintignant won the Buenos Aires F1 event that preceded the main championship race. However this turned out to be the last major win for a T51, as the speed of the new Lotus 18 raised eyebrows around the paddock. On the journey back, John Cooper made his mind up that to stay at the front he needed to build a new car, and at the next championship race at Monaco the lowline T53 made its debut. In the meantime Moss took the Walker T51 to second in the Glover Trophy and qualified on pole position for the International Trophy before retiring with wishbone failure. Rob Walker had already bought a Lotus 18 for Moss, but ironically the Englishman was to miss a large part of the season through injuries sustained when his notoriously fragile Lotus lost a wheel at speed in Belgium. Cooper entered the T51 just three more times, with Scarab refugee Chuck Daigh and journeyman Ron Flockhart retiring each time.