The first prototype Leyland National B701

By the autumn of 1969, the bodyshell of the first prototype Leyland National B701 had been built. It was built to the length of 11-metres and had two doorways. The body was painted in red oxide primer and before fitted out as a running prototype bus. The body was fitted with numerous strain gauges and was enclosed in a scaffolding frame. Sandbags were lowered onto the roof and the stain gauges measured how the body structure responded to the test weights, the result the body structure passed with flying colours.

 

B701 was fitted with running units, glazing and interior trim, which comprised of a few seats and a mass of electronic equipment to measure how the body structure coped with various tests which B701 would undergo. The livery used on B701 was gold with a darker gold skirt and a white roof, the livery was altered later. B701 used the original David Bache styling as seen on the wooden mockup, complete with recessed cove panels. Originally B701 used a small roof mounted pod but it was later changed to a larger pod.

 

B701 was registered XTC 351H to allow it to go overseas for testing. B701 would be subjected to brake and suspension testing, in 1970 B701 would spend eight weeks in Finland for extreme cold testing and then B701 would spend eight weeks in the heat of southern Spain. It was when B701 went to Spain that the livery was altered.

 

B701 would be used for the famous crash test K1A when it was impacted by remote control at 20mph into a 100 ton reinforced concrete block at the Transport Road Research Laboratory (TRRL) at Crowthorne on 25th October 1972. For this test B701 was painted into an allover yellow livery with black markings, it was also fitted with the production panels.

 

This official Leyland publicity photograph shows B701 undergoing suspension testing, note the crude entrance and exit doors, also note the script B701 behind the entrance doors. The new low profile 11/70 tubeless tyre developed by Goodyear can be seen clearly in this photograph. Later in its life B701 was fitted with sliding side window ventilation extra driving lights and Leyland National badges, certainly when B701 was in Spain it had these modifications fitted. In this view the recessed cove panels alleged for exterior illuminated advertising have been replaced with near to production cove panels.

 

B702 was the first drivable prototype due to the fact the body structure of B701 was under going static testing. B702 was a 11-metre bus and fitted with a naturally aspirated 500 engine. Most of the prototype B7 buses seem to change liveries along with modifications made to the exterior. All seven prototype B7 buses were built at Leyland South Works. Only B705 registered BTJ 857J was fully fitted out and used at the Earl's Court launch in 1970 and wore an attractive gold livery with a white roof.

 

The reason that the Leyland National used a roof mounted heating and ventilation system housed under the large pod was because it was near the engine and eliminated the need to have miles of pipes to feed floor mounted heaters. Sadly, warm air can only rise and not fall. To keep costs down, the production Leyland National only had one heater unit rather than the two used on the prototype buses.

 

 

Photograph credit: British Leyland Truck & Bus Division/Basil Hancock

 

Bibliography:-

 

Books: Leyland Bus Mk2 Doug Jack, Beyond Reality, Leyland Bus the Twilight Years Doug Jack

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