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.

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

On the 339


The railway came to Ongar on April  24th 1865 and the line from Leyton was taken over by London Transport on September 29th 1949 the section from Loughton being worked by steam until 1957.  On September 30th 1994, the line east of Epping was closed. Now, The Epping and Ongar railway (www.eorailway.co.uk) operate steam and diesel trains over this line. The name is a slight misnomer as the trains don’t quite reach Epping!  To bridge the gap, a heritage bus service runs to and from Epping Station. As a result of an invitation from Mike Kay, a tour manager with Friends of London Transport Museum, I found myself in this part of Essex, not far from where I was brought up, over the Spring Bank Holiday weekend. Most of my bus driving since I passed my PCV test in June 2011 has been on Bristol buses with crash gear boxes, but this weekend was going to be RTs, with pre-selective gearboxes. I had driven one before, for about 20 minutes! This was going to be a learning curve. I was on duty 1 for service 339 which, in its London Country heyday, ran from Harlow to Warley but now runs from Epping Station to Shenfield Station. Mike was to be my conductor and the bus we had been allocated was RT 3238.

RT 3238, with Mike Kay, at Epping Station.

RT 3238, with Mike Kay, at Epping Station.

Start point was Blake Hall Station, once famous as the least used station on the whole underground network but now a private residence. I arrived  about 15 minutes before I was due to leave and found Mike in the station house, with Roger & Wendy who run Epping & Ongar Railway, and was offered coffee and toast. Several slices! I only accepted one!  Then to the bus and Mike turned off the battery isolator whilst I carried out my walk round checks. All in order, and we set off to Epping Station. No real problems along the way, which did give me time to re-acquaint myself with this type of gearbox. However, on arrival at Epping, I did see quite a bit of green foliage trapped by the upper saloon front windows! I’m driving through Epping Forest, and on the approach to Epping, trees completely cover the roadway. You’ve got no chance of avoiding them and it’s very difficult from the cab to judge which branches are low enough to strike the front of the bus. I decided to take it a bit slower on the return. The first three trips on duty one are shorts between Epping and North Weald Stations and I soon learnt that the timetable wasn’t quite as  tight as I feared. The bus was able to hit 40mph but was much happier cruising along at 35. I think it was the second trip into Epping where I got one bell to stop. Somewhat puzzled by this, as we had no passengers on board, and Mike couldn’t see the bus stop. I stopped, and Mike told me to hang on for a minute. He re-appeared with a cup of coffee! I’ve no idea where he procured it from but later, I realised he knew just about every coffee stop and fast food outlet on the whole route. We arrived at Epping Station where we had a short layover, just enough time to get a bacon roll! Mike had also, very kindly, provided me with a packed lunch. Sandwich and a piece of fruit? I later totted up the calories in that bag and it came to over 3500 calories! That didn’t include the bacon rolls and toast! After three trips, we arrived back at North Weald for a one hour break, spent in the refreshment carriage in the station. I declined the offer of a sausage roll! This break did give me time to reflect on my driving and the bus. It is superb! Very easy to drive, once you get the knack of using the pre-selective gear box.  More than once, I found myself pressing the clutch(!) pedal as the bus came to a standstill, as you would with a crash box bus but eventually, I got out of this habit. The cab is rather Spartan as you would expect for a bus of this era, but despite being quite high off the ground, surprisingly easy to get into. Whoever designed it clearly considered the possibility that drivers might want to get in it, unlike the Leyland Tiger and Bristol Ks that I drive! The toe hold is in just the right place to enable you to clamber up, and at 5′ 4″, I’m not the tallest of drivers! After our break, we have another journey into Epping, followed by a trip to Ongar, still in RT 3238. Going along Epping High Street, there is an interesting pinch point. I’m not sure if it was designed as such, but it makes life a bit hard for drivers of wide vehicles. There is a pedestrian refuge in the middle of the road but unusually, cars are allowed to park on the nearside. Even if they manage to park inside the broken white line, it’s fairly tight and I have to take it very slowly. I do notice that the kerb stones of the refuge show signs of being trampled on by something heavy.

 

Later that day, I find myself driving a slightly different London bus, RTL 1076. AEC (Associated Equipment Company) built 4825 RTs for London Transport but a further 1631 buses were built by Leyland and designated RTL. To all intents and purposes, they were interchangeable and bodies were swapped between the two when at overhaul at LT’s Aldenham works. The most obvious difference in appearance is the radiator but I was told of another difference for the driver, how to stop the engine! For the AEC variety, you lean forward and pull up the accelerator pedal but for the Leyland, you pull a knob to the rear of the steering column attached to a wire running to the engine. Well, in theory at least,. but in practice, I was advised to move the gear selector to 4th then press the gear change pedal. Much the same as I do on the Leyland Tiger PS 1 I drive. You also have to remember to put the bus back into neutral afterwards!

 

RTL 1076 & RT 3238 at North Weald station

RTL 1076 & RT 3238 at North Weald Station

So, onto the open road. This journey was to Shenfield Station and gave me time to get used to this particular bus. The only differences I noticed were that the steering seemed a bit heavier and I found it hard to keep a steady pressure on the accelerator pedal. I had to keep my right heel firmly anchored to the floor otherwise the engine speed would rise and fall.

Just south of Ongar, there’s another pinch point, or chicane! The A128 passes over the River Roding at Langford Bridge. The road becomes a dual carriageway, but each is somewhat narrow, with s-bends on either side. There’s a 30 mph speed limit, but I’m doing considerably less! This is down to 2nd gear and slowly inch between the crash barriers on either side. I’m relieved to emerge out the otherside without making contact with anything!

From Shenfield, we have a trip to Epping then back to North Weald where we finish for the day, apart from taking another empty RT back to Blake hall Station. A wonderful day’s driving, loved every minute of it.

Sunday is a repeat of Saturday, duty 1 on the 339, with Mike as my conductor. Only change is that I drive two RTs, 3228 and 3238, during my shift. It’s still a marvellous feeling to drive these buses and I’m really enjoying it. It has rained overnight and Roger asks me to check that the water isn’t weighing down any low branches along the route. I’m still a bit nervous about these as I’m not really sure how to avoid them, all I can do is slow down when I approach trees that look as if they might catch the top of the bus. At the end of each run, I got out of the cab to check for damage, but can’t see any. I’m also getting a bit more confident about driving through the two pinch points, although I don’t increase my speed.

Green Line RT 32389 at North Weald Station

Green Line RT 32389 at North Weald Station

 

Sunday’s duty comes to an end far too quickly, I must still be enjoying myself!  Monday has a couple of changes. Mike has gone back to work and my clippie for the day is Katie. I’m on duty 2 this time, which has a later book on time of 9:45 at Blake Hall. I arrived there slightly early and was glad to be offered a cup of coffee and some toast. My bus for the morning is RTL 1076 and I set about my walk round checks. My first drive is off service to Shenfield Station, where I’m to pick up Katie. I also have to remember to pick up her ticket machine box before I leave, something that, I’m told, hasn’t always happened in the past! On the road, I still find I prefer the RTs but I seem to be getting more used to the RTL. No problems on the road and I get to the terminus just about on time. I notice several intending passengers at the stop on the other side of the road, and I’m rather relieved to see Katie there as well. I’m not sure what plan B was if she hadn’t turned up!  The turning point at Shenfield is around a small triangle of land after the railway bridge. It’s tight, and the lack of power steering means you get to exercise your arms! Once on the stand, Katie came over to retrieve her ticket machine box and shortly after, she gave me two bells to pull away.  Duty 2 then involves a long run up to Epping followed by a trip to Ongar. The turning point there is also a small triangle of land by The Two Brewers public house.

 

RTL 1076 at Ongar, Two Brewers

RTL 1076 at Ongar, Two Brewers

 

From Ongar, the bus returns to Epping but Katie and I get off at North Weald for a one hour break. Excuse for more coffee! As I sign off my time card, I notice Wendy on the platform of an RT, so I ask her which bus will I have after my break. She checks her roster, then says I’ll be driving the RM! Did I kiss her? I could have!!

 

RM 1966 at Ongar, Two Brewers

RM 1966 at Ongar, Two Brewers

Now I have driven a Routemaster before, but only once and probably not much longer than my first drive of an RT! Would it all come back to me? Lunch over, Katie and I watched the Routemaster come in from Epping and then I climbed into the cab. Getting in is just as easy as the earlier types. I see Katie is ready, so I press the starter. Nothing happens! Well, moment of panic, then I look down to my left. The engine stop is a knob on a wire leading into the engine, and it’s still in the “out” position, so I push it back in and hear a click from the other side of the cab. No idea what that is but the starter now works. Two bells and I’m off. First thing you notice is how easy it is to turn the steering wheel. The power steering is a real boon when you need to turn the bus around in the confined space of the station approach. We’re heading for Shenfield for this trip and I take it slowly up to the main road to get the feel of this bus. Then onto the road and through the village of North Weald. The bus is a delight to drive and I can understand why it was so popular with London drivers. I don’t know if this particular bus still has an auto gearbox function, but I drive it in semi-auto mode. It just appears to lumber along the road with seemingly no input from me. No problems getting to Ongar then I have to negotiate Langford Bridge, with a bus that’s 6″ wider than the RTs! Take it slow. As my instructor told me, the smaller the gap, the slower the speed. I’m not sure how slow I went but I was keeping a very close eye on my mirrors!

 

 

RM 1966 at Epping LT Station with Katie

RM 1966 at Epping LT Station with Katie

 

As you can see from the above photo, I successfully drove the bus back from Shenfield, through the chicane at Ongar and the pinch point at Epping High Street.

Driving up from Shenfield, I arrived at The Two Brewers about three minutes early, so waited there. This didn’t meet with approval from all the passengers. I was due to leave Two Brewers at 15:00 and Ongar Station at 15:02 but one of the passengers pointed out that there was a steam train due to depart Ongar at 15:00! Integrated public transport is still a little way off! After arriving at Epping, I had another round trip to Ongar and a note on my time card warned me not to leave North Weald before 17:00 or risk leaving the last passengers on the train stranded.

The Last Journey!

The Last Journey!

 

 

 

I made sure no one was left at North Weald then headed out to Epping, and through the pinch point for the last time. I don’t know if I was just lucky, but I never encountered any cars parked there that weren’t over the line so I was able to squeeze through without mishap. Then at Epping, Katie left to head home, after depositing her ticket machine and completed waybill with me, and I made the final trip to Blake hall Station, enjoying every last second!

At Blake Hall, I parked up the bus and handed in my time card. Wendy very kindly offered me a cup of coffee before I started out on the long trek home, hoping the M25 wouldn’t live up to its reputation as The World’s largest car park!

 

End of the Day.

End of the Day.