seraphim

I'd never heard the term "Crewe Cut Cab" before - officially it was the Crib Rail mod. For the Porterbrook-owned 47/8 fleet, most were done at G exam in the mid to late 1990s, and were outshopped in either Exec livery or (later) Virgin.

As a youth, a favourite train-spotting location was Hest Bank crossing, on the shores of Morecombe Bay. One day, a lady walking a small dog was stopped at the (frequently) lowered barriers. She choses not to use the footbridge. Instead, she ties the dog's lead to the barrier, and watches the train pass. You can guess the rest...

I visited this line some years ago; mid-way through the journey, we stopped for a military re-enactment (1914-18 period stuff). Not 100% sure what side was which, and given the complex history of the area, felt best not to enquire too much. Once the battle was over, the loosing side was taken prisoner. And then lined up and shot (not for real, I hasten to add...).

And how could I forget my least favourite coach of them all - 12140? Never fitted with BT10 bogies, it had at least two different designs in its life, ending up on BT46 bogies similar to MkIII DVTs. But only similar - not identical - and hence becoming a nightmare at each and every bogie overhaul. I was promised a trip to the breakers on the day it was cut. Bit like going to a funeral "just to make sure".

Others beat me too it, but I'm fairly sure the photo is the BT15 bogies. Ended up under scrap sleeper cars if memory serves. There are many, many different sub-types of BT10 bogie, but the main ones are as follows:- - BT10A - early type with bolted joints securing the lateral control rod brackets to the bogie frames. This area was found to be prone to cracking, which led to... - BT10B - where the LCR brackets were formed of a casting which was welded into the bogie frame. BT10A was not permitted for use on HST. I have never heard of a BT10C (and I wrote the bogie overhaul manual....). Sleepers were late build, and consequently were built with BT10B bogies. In theory, BT10As could have been fitted (being LHCS, not HST, vehicles. But the reality was that the overhaul processes for Sleepers kept their bogies in a self-contained pool. There were allegedly some "special" BT10s with beefed-up platework used on the Royal saloons based on MkIII bogies. But I never dealt with those (and never saw one). Other main variations:- - Long and short swing link bogies. LSL bogies were the original design, and rode better (it's a principle that the longer the swing link, the better the ride). But they also had a minor gauge infringement which was an issue on 3rd rail lines. So, XC HSTs, which went to Bomo, had to be 100% BT10B SSl. - Wheelslip types - at least four types - Girling self-powered, Girling Coach powered (both rubbish), BR MK2 (less rubbish) and Westinghouse (pretty good). Add into the mix that different types of coach had different spring arrangements. Yellow and Green springs - and the famous GNER yellow springs which were painted red because it looked nice. Keeping on top of this lot made for a busy existence.

The "air motor" is the cylinder used to raise a pantograph. On a loco, it sat on the roof and raised the pan through a linkage. APT-P had the issue that the pantograph didn't tilt, whereas the bodyshell did. Hence the air motor being fitted in an unusual location.

I pressed "send" last night, and then realised I forgot to mention the key technical innovation which enabled Creep, which was the doppler radar. Traditional wheelslips worked by comparing axles - such as the "current balance/imbalance" system discussed above. The problem is that such systems don't detect all-axles slips. To allow creep, the control system must know "true ground speed", which - by definition - cannot be measured by a traditional axle-based speed probe. Hence the use of doppler radar to achieve this. Class 60 basically pinched the Super Series idea, although Brush argued that they took the concept and improved it. Cynics would say "made over-complex and unreliable". I couldn't possibly comment. The spec for Class 60 stated that it had to acheive 500kN tractive effort (the equivalent for Class 59 was 509kN). I was on the Class 60 project at the time, and there was dancing in the streets on the day that the first loco got to that magic number recorded by the Test Car. Answering a couple of other points made. The SEPEX control scheme, as trialled on 58050 and then incorporated on Class 90 (and probably 91, unsure, never worked on them) seperated the circuits for traction motor armature from motor fields; a traditional "series wound" motor had the field in series with the armature (hence the name). This meant that one can control the motor and the armature currents (basically) as one variable. SEPEX allowed independent control of field and armature current, and hence - in theory - improved ability to control slips. As an aside, Class 90 was SEPEX and had Doppler radar from new; the radar was disconnected very shortly after, as it was unrealiable and there were concerns about axle strain - basically, one wheel slipping but the wheel on the other no slipping, leading to "winding up" an axle - by very small amounts, but nonetheless a Bad Thing. The redundant radar housing was an evil head-bang hazard with painful memories. It's slightly unfair to describe the engine in a Class 59 (the EMD645) as harking back to 1938; the EMD engine is an evolution, in the same way that one of the 1980s GEC Ruston engines was an evolution of the engines fitted to 10000/10001. That said, it you stripped down a Class 66 engine, a Class 59 engine and a WW2-era 567 engine, you'd be hard-pressed to tell them apart. The supercharger is driven by an over-running clutch; once the engine gets to "fast enough", the clutch disengages and it becomes a turbocharger. This is necessary because, as a two-stroke engine, the EMD needs to be pressure scavenged. The clutch is what makes the distinctive metallic ringing noise on a Class 66.

My understanding of the key reason for 50149's lack of success as a freight loco was that "the project" refused to allow the loco to be set-up correctly on a load bank. With a generator-fitted loco, this is crucial. I was told this by one of the engineers deeply involved in the project. The EMD Super Series wheelslip control system was groundbreaking; the key was the recognition that optimum adhesion was achieved by the wheel rotating slightly faster than "true ground speed". There was debate about what the ideal "creep %" was - between 5 and 10% seemed to be the best.

The original HST catering vehicles featured keg beer. One of the official histories comments that this was discontinued due to "internal control issues" which sounds like a euphemism if ever one was.

My apologies for being unclear. The Astra van was a diesel and certainly did not have outrageous amounts of power. It also only seemed to have one gear when some people drove it. The on-call car was a Ford Sierra crossed with an Audi Quattro. I was once stopped by the Constabulary driving a BR Ford Escort. It said British Rail in huge letters across the back window. First question - 'Is this your car, Sir?'

Exploring the load limits of the depot Vauxhall Astra van. There was an urgent need to move brake blocks, for reasons too complex to explore. Putting a pallet in the back of the van resulted in the front wheels having clear air under them, which didn't seem like a good idea. So, split up the pallet and spread the blocks over every horizontal surface in the van, including the front seat well, the front seat, you get the idea. OK, so now we have some semblence of steering, but braking.... An on-call car which seemed to have been procured by a Scandanavian rally driver. Outrageous amounts of power, rear wheel drive, and handling not helped by (again) criminal levels of overloading (you never know, that spare traction motor could be just the thing...). The car was notorious for the rear overtaking the front in rare UK conditions, like it having rained in the last month, or roundabouts, or pretty much any change of accelerator setting.

Reading Depot used to have a member of staff who came to work in some sort of armoured vehicle - I think it was a Humber Pig, a vehicle often seen in the 1970s in Northern Ireland news stories. It was something of a talking point. I have a number of stories about BR road vehicles, but am unsure on what the statute of limitation is on motoring offences....

In the early 1970s, my Father would take me to Hest Bank level crossing, just north of Lancaster. Being small, I head to peek through the many gaps in the wooden footbridge to be able to see the trains. Some trains were unbelievably loud; hindsight suggests that these were pairs of Class 50s on angle-Scot expresses. And then one day we arrived, and the old wooden footbridge was no more, replaced by a huge concrete and metal thing. Importantly, it had no gaps to see the trains through. Clearly, electrification north from Weaver Junction had arrived.

AS was sometimes found written in Class 85 loco repair books by exasperated depot staff "Drivers - if the blower motor is full, please use the Urinal".

I believe the Combino issue was that the integrity of the bodyshell could not be guaranteed in some accident scenarios. I think the bodyshell was beefed up in some areas, but don't have any detail on that. The problem with that type of fix is that it then pushes the problem elsewhere in the bodyshell - maybe to somewhere which can't be seen. I understand the similar Urbos3 fleet in Sydney has also been withdrawn from traffic. It will be interesting to see what effect there is on the Edinburgh Urbos2 fleet. The suggestion from Robert Shrives that this is linked to the battery mod is unfounded garbage. The whole point of the Urbos3 fleet was to allow battery retrofit, and the work was carried out by CAF themselves.