Titan

It seems you have a total lack of understanding on how a diesel electric transmission works. The motor/generator is the equivalent to the gearbox, providing an effectively infinitely variable gearbox. Changing the gear ratio on a train is like changing the diff ratio on a car, not sticking it in 4th or fifth gear, and the results are exactly as I have described as far as the train is concerned, due to the infinitely variable gearbox the electric motor provides.

Because gearing does not make that much difference, particularly when compared to power on a diesel passenger train? Take a Deltic for example. geared for 105mph max speed, full power available between 18.5 and 100mph. Re gear it for say 75mph, and you will only improve performance below 18.5mph, since tractive effort is entirely dependent on how much power you can get down. As both versions have 3,300bhp, available, they will both put down near as makes no difference exactly the same tractive effort, and therefore acceleration between 18.5mph and 75mph when the 75mph version runs out of puff. However, increase power to 3,600bhp with the same 105mph gearing, and the 3,600bhp version will have better acceleration all the way from 18.5mph up to 100mph and beyond, far more significant than the few mph you gain below 18.5mph that regearing alone would give you.

Very impressive!

The formula is quite simple, maximum gradient of the wire is 1 in (5 x line speed). So for 125mph that is 1 in 625. At a level crossing design wire height should be 5.8 meters. Under a low bridge it can be down to 4.3m, a difference of 1.5m. at 1 in 625 that will take 937.5m. You also need a transition at each end because you can't go from level wire straight in to maximum gradient, so adding a couple of spans at each end for that will take the whole distance to over a kilometre.

That was the other one I was thinking of but Webasto was easier to spell.

Presumably said on the subject of Maidenhead viaduct! Nothing new then...

If I have a small fiddly job to do I put the model in a clear plastic bag, and work on it with my hands through the opening. That way if something goes ping the carpet monster does not get a look in...

So they really did have a chip on their shoulder!

It is quite possible, grading down from maximum height to minimum height at a suitable grade for 125mph takes almost a kilometre.

Kind of sticks two fingers up at those who seem to think that running a model freight train at more than a crawl is unrealistic...

I would expect they have a Webasto diesel fuelled heater or similar plumbed in to the cooling circuit. I have a small one on my car, turn it on 15mins before I leave and I have warm interior, warm engine and defrosted windows before I even turn the key...

What a disgustingly uninformed post! Who told you there is precious little left? There are innumerable examples of Brunels work left, almost all of 'His Finest work in England' and most of his lesser work too, including Steventon Bridge, which is typical of many of the bridges over the GWML. There are bridges that have been widened to four tracks, and had the width of the road increased perhaps a hundred years ago, but because the original part which you can't even see is still more or less intact under it all the whole damn bridge is listed. I only worked on a 20 mile stretch of the GWML, but there must have been over a dozen listed bridges in that stretch, and that was before stations, buildings etc. were even counted. Over the whole GWML there must be hundreds, if not thousands of surviving and listed Brunel structures, many of them almost identical. Almost all the Brick overbridges, and there are a lot of them, will have something dating back to Brunel and will be listed.

They were built at Crewe, possibly on a test run to Preston and back?

Many of the prototype pacifics are not pivoted, they effectively have an axle with a lot of sideplay, known as a Cartazzi. Almost all LNER pacifics are like this and I suspect a good many others too, see here: https://en.wikipedia.org/wiki/Cartazzi_axle So having it not pivot is more accurate, but it will of course look poor on unrealistic curves...

But the braking system fitted never became obsolete, so it is a fictional point with no relevance. Had those locos been vacuum only when preserved, you can bet they would be even more insistent on a change to air brakes than we are!

Unfortunately anything with a hint of Brunel seems to get listed, irrespective of whether or not there are dozens of similar examples in existence. It would not surprise me if over half of the bridges on the GWML were listed...

Unfortunately it is very easy to get completely focused on the railway side of things in these situations. Highways also have standards which have to be complied with, which includes maximum permissible gradients on roads. The bridge in question appears already to have a grade up to it of some significance. In order to lift the bridge it may also be necessary to regrade the road for 1/4 of a mile or more either side. When you have junctions close to the bridge then the junction and the roads joining it will have to be rebuilt and regraded too, and since they are often graded up to the junction they may also need regrading for some significant distance as well. If there are properties next to the road then you have further problems - you can't lift the road and put it on an embankment in front of someones front door! Indeed the road is already on a low retaining wall outside the Cherry tree pub as it starts its climb to the bridge, so it has already been lifted here which would suggest that the road is already at the maximum allowable grade already, if not worse and a 1m lift (and possibly more) outside the pub to keep the road compliant would not only lift the road to somewhere near first floor level, it would completely screw up the access to the pub car park, not to mention Station yard and Pugsden Lane! It might even have been the case that Brunel built the bridge lower than he would have done otherwise because of this... It can get to the point that in order to lift a bridge then half the surrounding area has to be lifted too, which can be totally impractical let alone affordable. Looking at the layout of the roads and buildings near the bridge, it looks pretty close to falling in the above category...

That is only true of the delays that are Network rails responsibility. Any fines that are not NR's responsibility they will recover from the TOC that caused the delay, not the taxpayer. The notable exception being charter trains...

What led you to that conclusion?

In the railway case it is not cyclical payments, indeed very little of the fines if any get back to DfT. The money collected as fines goes to the TOC(s) that have been delayed. Passengers can then reclaim the money through the 'delay repay' compensation scheme. If all those members of the public eligible for compensation make a claim, and in my experience there are usually plenty of on train/station announcements informing them on how to claim, then a significant amount of that money will end up with the passengers that have been affected, the remainder compensating the TOC(s) for loss of business/harm to reputation etc. So in the railway terms it is far from just a paper exercise, it is a real and significant monetary loss for Network Rail which does not end up with the government.

Not only that, but if the above figures are somewhere near correct, the 323 is putting less horsepower through each powered axle despite having more power overall.

Have you or anyone else ever slipped to a stand in a 323?

When D9000 was built it had an experimental Xenon flashing headlamp installed and no central footstep. These must have been fitted in lieu of the footstep that the the other Deltics had as standard, otherwise there would have been no footstep at all. When the light was removed it was replaced with a smaller bespoke footstep in the light aperture, to bring the provision back in line with the other class members - and reduce the risk of someone not paying attention missing his footing. This made the extra ones redundant and they were removed at a later date.

Trains don't crash every day full stop. Even if the eventual brake power is the same, A vacuum brake takes a lot longer to apply to full service or emergency, at least an extra 10 seconds if not more depending on the length of train. To take just one example, The driver of DP2 reacted very quickly and applied the brakes fully at about 80mph or so. In 10 seconds you travel a long way at 80mph, a couple of hundred yards at least. Had the train been fitted with faster acting air brakes, of identical brake force to the vacuum, even if it could not stop it would have been traveling much more slowly than the 30mph or so it managed with vacuum brakes. This would have resulted in much less damage to DP2 and the following coaches. DP2 would have been repairable, and far fewer people would have died, possibly none. So yes, using vacuum brakes risks killing more people and doing more damage as proved by the above accident, and I am sure there are many other accidents where being able to get the brake fully on 10 seconds or more sooner would have significantly improved the outcome.

So presumably any offspring are more likely to be Ernies.