I’ve been reading through a British Leyland internal policy document from April 1971 that was commissioned to look at their three premium truck plants, Leyland, AEC, and Guy, and their future production. Leyland was producing at almost 100% capacity, AEC had been at 100% capacity but with the end of Routemaster bus driveline production it had spare capacity, and Guy was at about 80% capacity. Guy was the smallest plant and it was almost purely an assembly operation, the only manufacturing carried out was its own rear axle. One proposal discussed in the document was the closure of Guy with Big J production being transferred to AEC at Southall. A second proposal was the closure of AEC, but Guy and Leyland could not absorb AEC’s manufacturing and assembly capacity so that idea was a non-starter. Therefore AEC would build the new premium truck model (i.e. the Marathon) scheduled for launch in late 1973, (which was when it was announced). Interestingly at the date of this document the Marathon was intended to have proprietary engines fitted, what makes are not specified. However there is more than one reference to on-going development work on the AEC V8 engine, even though the Mandator V8 had been dropped 3 years earlier in 1968. Was the re-vamped V8 engine being considered for the Marathon if it could have been made reliable? In April 1971 there is not a mention at all of development of the TL12.
The individual “premium truck” production figures for each factory in 1970 are shown as follows. Unfortunately not all individual model totals were recorded.
AEC Southall
Heavy Goods (Mandator and Mammoth Major), 2,111
Medium Weights (Mercury and Marshal), 2,803
Passenger Chassis (Reliance, Swift, Merlin), 1,342
Total AEC = 6,256 (78% of capacity)
Guy Wolverhampton
Big J 32 Tons GVW Tractor Units, 1,141
Big J Eight Wheelers, 68
Big J Medium Weights, 1,345 (including 1,080 with AEC AV505 engines)
Passenger chassis, 316
Total Guy = 2,870 (80% of capacity)
Leyland
Heavy Goods (Beaver, Badger, Octopus), 1,750
*Medium Weight Comet, 3,938
500 Series (Lynx, Bison), 796
Passenger Chassis (Atlantean, Leopard), 2,082
Total Leyland = 8,566 (93% of capacity)
- Note: Many of these Comets were an export model, not the Ergomatic Comets familiar in the UK.
A couple of other points. Firstly both Leyland and AEC had engine building capacity far in excess of their chassis building capacity. AEC bought in gearboxes from Thornycroft, and rear axles from Maudslay, both being Leyland group factories. Leyland bought gearboxes and some rear axles from Albion. AEC and Leyland Ergomatic cabs came from GKN Sankey, and Guy Big J cabs were sourced from Motor Panels.
Secondly, from the above production figures it can be seen just how large the medium weight (16 to 26 tons GVW) market was in 1970.
Robert
. robert
