Clean, sweet heat?*

I posted this image, of an aide-mémoire issued to Crosville bus drivers in the 1970s, a few weeks ago and wrote a few thoughts about semi-automatic gearboxes, as discussed in the card on pages two and three.

I did not refer to the fourth page which refers, as you might expect from the cover page, to the use of combustion heaters. At the time this was issued, it referred uniquely to Webasto heaters though later I came across Duple Laser coaches fitted with Eberspacher heaters which worked in a similar way. Essentially, a low combustion of fuel created heat and air would be blown over the unit to circulate the heat around a chamber in the side wall of the bus, to emerge from vents into the saloon.

You can still buy these heaters [albeit new models] brand new today – one will set you back about £3000 – and perhaps they are still a regular feature of 21st century coaching. I don’t get out much on modern coaches to have any knowledge of that.

The problem with Bristol-manufactured coaches in the 1950s, 60s and 70s was that the engines were sometimes too efficient: Gardner engines were renowned for fuel economy and running cool. In the winter the driver of a Gardner-engined bus would often be seen in his cab wearing an overcoat. The day’s Daily Mirror might be stuffed over the radiator grille to try to keep some heat in the bus’s cooling system. In a coach this could cause mass hypothermia if a coachload had to sit there for four hours or so with inadequate heating. So the combustion heater could be called upon to heat the saloon of such a bus effectively.

Crosville had these heaters fitted to most of their coaches from the 1960s and also to some “dual purpose” buses fitted with coach seats in a bus body. The “DPs” operated lots of interurban routes where passengers could be on board for half an hour, often an hour or more. So the comfort of those people in winter became a concern. The 50 Seddon DPs of 1971-72 were fitted with Webastos as were the 24 1972-73 Bristol RELLs.

Crosville ECW-bodied RELH6L coach ERL267 heads a line of Crosville participants next to Sherdley Park at the open day arranged by St Helens Transport Museum in September 2010. The grille for the Webasto heater can be seen on the waist rail beyond the fleet name but ahead of the rear axle.

In later years the use of the heaters could be hit and miss. It was recommended to use paraffin [kerosene] but ordinary bus diesel did the job and was often used instead. It didn’t burn as cleanly. As the years went by, lack of maintenance could be an issue. Heaters would misbehave or simply not work at all. By the time I started driving buses the newest coaches in use were fitted with Eberspachers that nobody seemed to know how to fire and I suspect were not being filled anyway.

My favourite coach was a venerable 1974 RELH6L with ECW body [a lot like the one above] which we were using on local express services that were well patronised in the late 80s. It was the only one and the oldest coach in the depot but the garage allocators knew it was my baby and would allocate it to me frequently because nobody else wanted to drive it.

One morning I was driving to Liverpool on the X4 service which linked Runcorn and Liverpool via Widnes, Cronton and the M62. Ripping along the M62 I felt a bit cold, so when I had a traffic light go against me at the end of the motorway [the Rocket interchange] I fired up the Webasto during the wait. A short distance after the junction there was one of the limited stops where a number of passengers would alight so I pulled over to let them off and was about to pull away when a little voice called out… “driver”. Looking in my interior mirror down the bus, thick smoke was filling the saloon and the smell of sooty diesel was creeping forwards. This looks like a good time to take a look at page 4…

The procedure above must not have been followed to the letter by the last driver to use the heater [who, driving a bus which would have been relieved many times during the day, may not even have realised it was working]. The heater was probably still running until the bus was switched off in the depot leaving partially-combusted fuel in the system.

That morning, the fumes were unbearable so quick action was needed. A roof vent was pushed open, forced air ventilation was switched on and the door was left open as we drove away. No-one died and though almost asphyxiated the passengers were generous in their restraint. The X4 did cover the better parts of Widnes…

Do you have any memories of buses fitted with Webasto heaters?

* “Clean, Sweet Heat” was the advertising slogan adopted by Manweb to encourage the uptake of storage heaters in 1972. It featured on posters on the side of Crosville Bristol Lodekkas that year but I can’t find a photo of one. If you see one, please send me the link and I’ll post it here.

A thought for the pause

By the time I started to learn to drive buses, with Crosville in 1985, a bus driver’s left foot had little to do, except perhaps to give a sticking cab door a kick at the end of a shift. Certainly in the region in which I was working, buses didn’t have clutch pedals. The gearboxes were mostly semi-automatic and new buses were coming with horrible fully-automatic boxes that took the decision to change gear out of the driver’s hands altogether.

Nevertheless, the thinking at Crosville at the time was to use venerable Bristol Lodekkas with “crash” gearboxes to train drivers, since if you can drive one of those you should be able to drive anything. The mystery of the crash gearbox is very easily resolved. To stop the gears making an awful crunching noise you have to listen to the engine sound and just as the engine is revving at the right speed for the next gear, foot down on the clutch and shift the gear lever just at the same time as the foot is going down.

Changing up the gears is straightforward enough… clutch down, release gear, wait for revs to die, then clutch/select next gear in one co-ordinated move. The tricky bit is changing down where, once the gear is in neutral, the engine needs to be faster to change down, so has to be revved up, but just the right amount for the particular road speed in that gear. It takes a little while to get the hang of it but you get an ear for it.

Crosville G220 in Ince on one of the days I was learning on it

Back in the 1960s Bristol Commercial Vehicles, which built almost all the new buses for Crosville in that decade, had a reputation for making life hard on drivers with these crash gearboxes whilst their competitors were fitting their vehicles with synchromesh gears [which could be changed in one go like a manual gearbox in a car] or preselector gearboxes with electric or air-operated selectors. But a new invention came on the market and by 1967 Bristol finally gave companies the option of buying their buses with controls that made life much easier for the driver: the semi-automatic gearbox!

I will deal with this booklet in two parts since the semi-automatic gearbox and combustion heater were two very different things.

The gearbox is described as a very intricate and expensive luxury, to be treated with respect. …

As you can see from these instructions, the gearbox was designed to be changed in a similar procedure to the crash gearbox but without the need for a clutch pedal and without the risk of failure. These gearboxes were tolerant, unlike the manual counterpart which demanded absolute precision. Similarly changing down:

I have to say that I followed this guidance when driving… it wasn’t hard to do. But there were lots, and I mean lots of drivers who realised that the gearboxes were very tolerant of being slammed from one gear to the next with little loss of power in the process and so better acceleration. So pausing between gears on these devices became something of a rarity as the years went on. Sadly that reduced the life of the gearboxes and added to the cost of bus operation through the need to replace gearboxes prematurely. Gearbox abuse was considered such a serious problem by the National Bus Company that they got Tony Bastable in to give the drivers a jolly good ticking off.

I will leave you with a link to that very video all trainees had to sit through, me included, in a room at Sealand Road Works. They Don’t Grow on Trees

And another, the Wikipedia entry for Self-Changing Gears