HOW TO DRIVE A BUS WITH A PRE-SELECT GEARBOX

Jo Jo

Back in April, I published a post on how to drive a bus with a crash gearbox, and was pleasantly surprised at the response it generated. I did say that I was hardly an expert on these buses, but wrote to the best of my experiences. It has been suggested that I do another post on a subject that I’m even less of an expert at. Pre-selective buses.

My first drive of one of this type of bus was only May 2014, just over a year ago! But never mind, here goes.

Pre-select gearboxes have been around for some time. Daimler cars were fitted with them in the 1930s and AEC RT type buses had these from 1939. I know there are some surviving Daimler buses with pre-select gearboxes but my (limited!) experience is from driving buses from the RT family thus what follows is based on that. These buses were, by any standard, extremely  successful. AEC built 4825 examples  for London Transport, designated RT, Leyland built 1631 virtually identical buses, designated RTL and  another 500 8′ wide models designated RTW thus the RT family was almost 7000 strong in London alone with further examples being found across the Country.

Right! Climb into the cab and what do you find? To the left of the steering column is the gearstick, mounted horizontally. 1st and 2nd are on the lower slots, 3rd and 4th on the upper. 1st and 3rd are away from you. Reverse is beyond 1st, pull out the silver safety stop to access it. The lever is sprung upwards so its tendency is to find 3rd or 4th. What you have to bear in mind is that this is a gear selector, not a gear changer. Now look down. You have three pedals, accelerator to the right as you would expect, brake in the centre and what looks like a clutch pedal to the left. Except that these buses don’t have clutches! This is the gear change pedal. The drive from the engine to the gearbox is via a fluid flywheel. If you’re not familiar with this concept, the US Defense Dept. produced a very informative film on this subject back in 1954 and it’s available on Youtube. https://www.youtube.com/watch?v=xm8EHTTNPEg

Fire up the engine. The starter is to your left above the emergency window, and looks like a coat hook! If your bus has been standing for any length of time and the air pressure has dropped, then  a red flag saying “STOP” will drop down from the top of the windscreen. If this is the case, leave the engine running while  the air pressure builds up.

Once you have sufficient air pressure, and assuming the walk round was satisfactory, you’re ready to go. Move the gear selector into 2nd gear. Nothing happens! Press and release the gear change pedal. The bus will rock slightly as the gear engages and the engine revs will dip. Move the gear selector into 3rd. Release the handbrake and the bus will move forward, in 2nd gear, press the accelerator to pick up speed. When you’re ready for 3rd gear, come off the accelerator, press and release the gear change pedal and you’re in 3rd. Move the gear stick into 4th, as that’s probably the next gear you’re going to need and when the time comes, press and release the pedal. It’s that simple! Well, not quite! Unlike a crash box, when you press and release the gear change pedal, whatever gear you have selected, will engage. You will not hear a nasty metallic grinding noise if you get it wrong! However, if you press and immediately release the gear change pedal, the bus will jerk, which is not good for your passengers. Now I haven’t been told this but what seems to happen is that depressing the gear change pedal disengages the gear you’re in, releasing it engages the gear you’ve selected. Thus, if you depress the pedal and hold it down for a couple of seconds whilst the engine revs die down, then releasing it gives you a much smoother ride. Similarly, going from 4th to 3rd, depress the pedal, hit the accelerator and increase the engine revs, then release the pedal gives you a smoother change down.

Once in 4th gear, I then move the gear stick back into 3rd. if I encounter slow traffic, it’s a simple matter to drop the bus into 3rd but if I have to stop, the bus will happily do so, in 4th, without stalling. See the Youtube video. When the bus comes to a standstill, move the gearstick into 2nd, press and release the gear change pedal, move the gearstick into 3rd and you’re ready to resume your journey.

You do have to keep your mind in pre-select mode. There’s a great temptation when the bus rolls up to a stop, to think you have a manual gearbox with a clutch and you must hit the clutch pedal or the engine will stall. Slap your wrist if that happens to you!

There are a couple of things not to do! If you have your foot on the gear change pedal, don’t move the gear selector, or vice versa.  That could damage the gearbox. And when you’ve finished with the bus, never leave it in gear. Next morning, someone is going to have real problems starting it up.

To stop the engine,  with the AEC examples, pull the accelerator up until the engine dies. The Leyland examples have a wire running up the back of the steering column with a knob at the end. Pull that up. Now in some buses, that works fine, in others it seems to be ineffective. What I was told to do in those cases was move the gear selector into 4th, press and release the gear change pedal and stall the engine. Not sure how good that is for the bus but it did seem to work. Just remember to then put the bus into neutral before you walk away.

If you do get the chance to drive one of these machines, they are fantastic buses to drive and very easy, once you get your head around the idea of pre-select. Have fun!

RTL 1076 at Ongar, Two Brewers. A Leyland example of a bus with a pre-select gearbox.

THE HESTERCOMBE EXPRESS!

This was my first outing with Crosville Motors this year, and a reasonably easy job. Crosville have linked up with The West Somerset Railway to provide a link on Wednesdays from Bishops Lydeard Station to Hestercombe estate. Thus June 17th found me at Crosville’s depot in Weston super Mare. My friend, BusmanJohn had done this trip previously with a Bristol L single deck bus but as the weather forecast was promising, I had been allocated an open top Bristol FSF. This old girl is quite a rare breed! the longer FLFs proved much more popular with bus operators and not many examples of the shorter version were produced.

891 VFM at Crosville’s Weston depot

First job is making sure your bus is ready for the road, and here came the only really embarrassing moment of the day. I couldn’t find the battery isolator! It wasn’t where I expected it to be, so I had to find a mechanic and ask. Turned out it was in a really obvious place, but with the gloom inside the depot, I didn’t see it.  That sorted, I headed south.

Now I know other heritage drivers use the M5 but I try to avoid this. Not so much because being slow, you stand a good chance of being rear-ended by someone, but more the case that in the event of an accident, the authorities think nothing of shutting the motorway for a few hours and trapping you in the middle. Thus I kept to the A38 for most of the journey. This bus has a five speed box, so you can maintain a reasonable rate as you trundle along but even so, it was over 90 minutes before I rolled up at Bishops Lydeard Station. Then a minor embarrassment! I arrived at the eastern end of the station, near to the car park. Someone in WSR uniform saw me and came over. “You’ve never done this job before, have you?” I wondered how he knew! Turns out I should have taken the western entrance, the one with two no-entry signs either side of it! Yes, I saw these signs, but missed the rider underneath, except for buses! So with his help, I turned the bus around and entered the station by the correct route, and parked the bus up to the side of the bus stop, not on it, or I would have obstructed the service bus.

The station at Bishops Lydeard

Then time for a cup of coffee in the station cafe, and chat with the friendly staff there whilst I waited for the train to arrive. The train was due in at 11:33 but was running a couple of minutes late. Then it discharged its passengers, and I wondered how many had bought tickets for the Hestercombe excursion. No need to round up my passengers, I’d left the bus in full view of the platform, and slowly, they gathered by it, waiting for my ok to board.

Despite the weather, which wasn’t that bad, most settled for the lower deck. I called these passengers, the wimps! They seemed to like that description. Quick head count, so I knew how many to bring back, and a brief greeting to them informing them when the bus would leave for the return journey. Then off into the unknown!

891 VFM parked up at Hestercombe Estate

I had been told there was a coach route into Hestercombe, as Somerset is noted for its narrow country lanes, and it was easy to find and follow. A358 back into Taunton where Hestercombe was signposted on a brown tourist sign. It’s only when you get near to Hestercombe that the road narrows but I didn’t encounter any problems and drove into the estate 25 minutes after leaving Bishops Lydeard. I now had a rather long break. Three and a half hours! The estate had kindly offered me free entry into the grounds, and a £5 voucher towards the cost of my lunch! Not the most sunniest of days, but pleasant enough to spend wandering around the grounds, and a quick look into the various buildings on the estate. The site is on a hilltop and the views across the valley are breathtaking.

Well, time for the return to Bishops Lydeard. By the allotted hour, they had all managed to find their way back to the bus. I had issued a dire warning that the bus would leave at 3:45, whether they were onboard or not! Although I had allowed a little leeway for stragglers. Then I moved off, retracing my route back to the station. A bit more traffic this time. School’s out! But no real hold ups, and I made it into the station yard, by the correct route this time, and disembarked my passengers so they could catch their return train. Usual banter with the WSR staff, including the chap who’d put me right earlier, “Didn’t know they put sat-navs in Lodekkas”!

Safely back to Bisops Lydeard Station, by the right entrance!

Then the long drive back to Weston and the Crosville depot where I parked up the bus, completed the paperwork, and thought about driving back home!