After so many years of working with, and being around, Routemasters, I thought I couldn't be surprised now at anything that is a either a feature or inherent curiosity.

This afternoon whilst cleaning the conductors recess area on RM 1563, I found something that was a real eye opener. Actually, it was more a case of shutting my eyes quickly when I unintentionally released a massive build up of dirt.

The rearward edge of the conductor area (which has the Park Royal badge at the upper part) tapers downward to finish by tucking inwards above the battery crate and close to the clip that was usually used to hold the old style coin bags. The two end rivets have failed causing a small gap - enough to get fingers in to. Sensing there was some dirt inside this void, I investigated further. I couldn`t believe how much `dry dirt` came out - literally handfuls - of fine, powdery dry black soot like dirt that must have been in there for years. So much of it which, presumably, has to be exhaust particles.

That sort of `black dust` used to be commonplace on the inner, forward end of the conductors area. I could never understand why this was supposedly the `conductors coat locker` complete with hook when the proximity of the exhaust pipe guaranteed that any coat put in there would come out filthy and stinking. It seemed a strange design `failing` that was, understandably, not used for its intended purpose.

Has anyone else ever found or released this dust `bomb`?

There also seems to be a lot of that sticky black soot/dust built up between the 'roof' of the conductors cubby hole and the stairs only reachable by a long thin vacuum cleaner attachment and with the outer panel removed. Also on top of the panel under the rear number plate once removed - obviously not touched for years. Will also check out your new dirt accumulation trap Neil !

My bus number (if any): RML2747

Ever tried taking the back pan off underneath? See how much accumulates there!

My bus number (if any): RML2532

Yes, Roy, it certainly does. But it`s expected there being so close to the ground - so no great surprise.

I couldn`t get over how so much dirt has managed to get into an area well above road height and seemingly `enclosed` by the structure around it. That was unexpected. There was no fluff or paper in the dirt - just fine exhaust like soot. Almost worrying to discover how much this stuff travels. I well recall from my days as a conductor how a uniform jacket hung up in the warm at home would always smell of exhaust and battery fumes. Far more so than my drivers jacket ever did.

When we prepared 1563 to be The Sales Department `demonstrator` it effectively had a mini overhaul during which we took the lower back advert panel off and found a Park Royal label on the back of it suggesting that no significant rear end damage had occurred during the life of the bus. Maybe a disproportionate amount of dirt has built up through the back end not being disturbed whereas other buses that have had a repair could look `cleaner` under the panels.

Some time back now I stripped down the back of RM 429 and 2129.

429 still had it's offside rear blind apparatus. But the cubby hole area was filthy and the whole stair area all the way to the rear offside bench seat was with the same carbon soot and water ingress grime.

I did 429 by hand and it took days to do. In the end I used a blue industrial cleaner which was slightly acidic and within a few hours most of the back panels and superstructure revealed was Chiswick Pink again and where that coating was still undamaged, the metalwork was perfect. But is did also reveal a fair amount of corrosion, particularly around the stairs, as well as a few decades of repairs which looked fine on the outside but not so clever on the unseen sides.

I recall travelling in RM196 from a rally and being near asphyxiated by fumes, even with windows open and an open platform and a cold evening to boot.

Later We had a real close look at the original type exhaust even blocking the end to detect a leak.

Nothing untoward showed up, no small holes or joint leaks. But for some reason, this otherwise smart bus was prone to the exhaust creeping in.

A year later after the strip down of 429. I checked the panels in 196. It was seeping up through the cubby area and the rear of the wheel arch area through the loose gaps in the inner panels. and it was the air draft through the gaps that was drawing the fumes up rather like a flue.

The cure ( carried out on 2129 and 429 ) was to use a flexible weather and oil resistant sealant on the panels at every joint with the exception of any drain holes.

Having recently rebuilt the back of 2532, I found much the same, with about 3 dustpanful's of dust and debris removed from the area under the stairs and the rear floor pans.

Last week the exhaust flexible failed and as Mark says, fumes were being drawn up through gaps and especially round the battery flap cover, left open at the sides t vent the batteries. No matter what bus you have, there's always hidden dirt! This can sometimes be a source of interest, especially ticket collectors. during my recent involvement with the Chatham & District Bristol, I took apart one of the set backs and found a goodly collection of tickets from the wartime and a few hand-written notes down the bottom of the seat back. Quite how they got there is a mystery as there's no way in for tickets or paper!

I also found an early ticket on MLL738, the BEA 4RF4 hidden under the back set. This was a Bell Punch ticket and was valid for travel from London Air Terminal to Heath Row Aerodrome! I put the ticket somewhere safe as you do, so safe in fact I've never found it again!

My bus number (if any): RML2532