The Leyland National and The NNRG

Over the past 40 odd years here in the North East we have been going about our business and traveling with a true British icon. The Leyland National was conceived by the then National Bus Company and Leyland Vehicles in A joint venture that was supposed to be the end for any other large rear engine single deck bus in 1970 and the prototype was revealed to the public at the National Motor Show in 1971.

Built using the integral construction technique the entire body was load-bearing. Indeed everything was secured to the body using Avdelock bolts. These had never been used in bus construction before. Indeed the National was the first fully integral bus made. The design was very futuristic and way ahead of its time. With only the driver its one-man operation was seen as an early cost-cutting measure.

While the bus was nothing that had been seen before some of the engineering could be traced back to other bus types from the Leyland family or AEC and Bristol. The engine that powered this new bus was something that had seen some success but in Leyland trucks. The 0510T engine was used but in A new horizontal format. This proved not to be the right way to go as the engine suffered from oil starvation to the pistons and camshaft resulting in a failure in cataclysmic ways with pistons getting thrown through the crankcase. This was eventually fixed and some 510,s would do huge mileage before overhaul. But not to today's standards. Cooling for the engine was provided by A radiator that was mounted in the offside of the engine bay. The fan was engine driven trough A shaft attached to the crankshaft damper then A toothed belt driving 2
sprockets. The actual fan was huge. Measuring 3 feet across it was mounted onto the drive belt sprocket. The gearbox was very similar to the Bristol RE. 

The braking system was the same as A Leyland Leopard. The steering ram was however A new design. The unit mounted onto the back of the front axle and was the entire steering linkage bar the shaft to the transfer box and column assembly. The rear axle was also new with the prop shaft going through the axle casing and then driving the differential pinion through 2 transfer gears housed in the front of the unit. Air suspension was used with a 2x2 air spring layout at the first 4 shock absorbers. the rear axle was mounted onto A-frame in the shape of an A. The front mounting was A resilient metaplastic bush. The front was mounted onto A subframe that was attached to the frame via 2 control arms.

Lateral movement was controlled by 2 Panhard rods. The interior was at first very sparse. Entering through the double doors at the
front and stepping up from the roadside via the single step you were greeted by the driver in his all enclosed cab. Then turning to the saloon the sight would have been all light tan vinyl seating. The offside bench seat could accommodate 5 passengers. the opposite was the luggage rack. Then the seats were 2x2 all the way to the back. To give room under the floor for the back axle engine and gearbox the rear saloon was elevated. the floor center sloping at around 4 degrees relative to the sides. This was the National phase 1.

With the learning curve that Leyland had been on with the National, it was no surprise that the National was undergoing some major modifications. The early phase 1 model was meant to have air conditioning. To this, the roof pod that housed the elaborated heating system was some 7 foot long. On phase 2 the pod was only half that side. The batteries were moved from the offside rear to the offside front to improve stability. The braking system was modified to incorporate a load sensor valve. This took over the distribution of the front-rear brake bias. the heavier the National was the more pressure was put into the front brakes.

All this was fine but the 510 engine was still troublesome at best. One National was re-engined using A Gardner 6HLXB engine. This meant that the radiator had to be moved to the front of the bus. On the Gardner powered bus, it was housed in An external frame that stuck out from the rest of the body. Leyland did not have anything to do with this mod. It was Crossville Motor Services' own. This did not mean to say Leyland did not take an interest...

In 1980 Leyland had decided that the engine problems with the National had come to Ahead. It was not good for business when the engine was only lasting some 150,000 miles or so. The National was subject to A complete redesign. All the things that were needed to be better were addressed. The main thing was the engine. Originally the National 2 was going to be fitted with the Leyland TL11H. But in testing the oil starvation problems were still causing issues. So the trusted Leyland 0.680 was used. This being A development of the 680/690 from the Leopard. The engine used the TL11H crankcase and compressor fuel pump layout but was not turbocharged and did not have the long swirl pot pistons that the TL11H was going to have. 

Major restyling of the cab and front and rear ends were needed to incorporate all the changes. The radiator was mounted in the front but the styling was used to cover this behind A rather nice looking grill. Braking cover this bus to me would be the main focus of my interest in buses from such an early age. My first contact with A National happened when I was 5 years old. My Aunt and I took A trip to Newcastle. The National was very busy and we had to stand near the cab. I remember the driver very vividly. He had short black hair and wore black sunglasses. The noise the bus made was quite something. It was fast as well or so I thought. Livery was, as I now know NBC Poppy red with A white stripe. I was hooked on these strange-sounding buses with A fan in the back. Later in life we would bike along to Stanley Depot on A Friday night and watch the Nationals come in. By this time I knew A bit more about them. Also I knew about the National 2 and there 3 types of engine. For now Northern had National 2,s with the Gardner 6HLXCT Leyland 680 and TL11H in them. I was hooked on them. I used to travel on Stanley and Consett's allocation of Mk2,s all the time. One took me to and from school every weekday. I got to know the buses by fleet number and soon I knew the allocation of Derwentside. The route I used was 700. On it in 1986 and 87 was A band of 7 orange Mk2,s 4660,4676,4678,4670,4700,4713,4714. Out of these all were 680 powered bar 4678,4670,4714. The Orange brand was competition livery
that had been adopted by Go-Ahead Northern. The fleet moved constantly from depot to depot. All together around 35 of the 60 Mk2 were orange.

Moving on. My first real close up of A National was A Mk1 at Shaws Coaches. This example was phase 1 ex Northern. It was out of service with engine problems and I was permitted to look around it. Next was when I working for Shaws and we got our 5 Mk1,s and 7 Mk2,s. I would look after the Mk2,s for some 7 years once they had passed into the Northern fleet once Shaws were disbanded in 1995 until there withdrawal from the fleet in 2003. When you're so hooked on something then its hard to let it go. So in 2005, I decided that I would buy one of there for myself. UPT 681V was one of the National 2,s that I looked after at Chester LE Street for A time. Volvo repowered as all 58 Northern National 2,s were she would need to get her engine swapped for a Leyland one.

Later in 2013, I would get my collection up to 2.. Another ex Northern example. FTN 710W. 4710 has gone from strength to strength over the last 4 years. Restored in the NBC Northern poppy red livery she is A striking example of her kind. Her restoration was started by the NEBPT in 2006. She ran for the 2008 season then was retired due to An oil leak. The Trust decided to part company with her and I was fortunate to save her.
Now she is the centerpiece in our restoration group The Northern National Restoration Group. On our books, we have 3 of the 4 surviving Northern National 2,s 4681, 4708 and 4710. My story is of commitment to a cause and determination to see it through. Quite fittingly we also have 2 of the Nationals replacements in the Northern fleet on our books. Volvo B10BLE Wright Renown 4855 and 4897.

Restoration and preservation go on in all shapes and forms. Keeping up with the times is something that I think is extremely important. You must save the transport heritage for further generations to enjoy.
That's preservation..