Edwin_m

I doubt it will be MMA doing anything. The combination of reinstatement costs, legal action, increased insurance premiums and loss of reputation means they will almost certainly disappear from the scene. Given that they've tried and failed to run the trackage at minimum cost I would have thought it was quite likely to be abandoned, and many other marginal short lines could go the same way.

Anyone who is intending to take legal action will want to be doing all they can to pin on the company rather than the employee, for the simple reason that the company (or more correctly its insurers) has more money.

They stopped running routinely in around 1990 and new unbraked wagons were being built up until about 1960 - no doubt somebody can give better dates. Something that should have happened much sooner in my view, and where North America and practically everywhere else was well ahead of the UK. There were many serious accidents with unbraked wagons over the years, and others involving other trains being derailed by the sprung catch points that had to be installed on main line gradients to derail any portion of an unfitted freight that split and rolled back before it could do more serious damage.

Those are useful updates Gerald but I think Chris is somewhere in the right ball park. If the wagons were overloaded this would increase the train weight but also by the same proportion the restraining force exerted by any wagon handbrakes that were applied, but it would slightly increase the likelihood of the train rolling away because the loco handbrakes (if applied) would still be the same. The question of damage to the loco (or indeed wagon) brakes on the journey downhill is not relevant to whether the brakes were sufficient to hold the train where it was stabled, although it would have some effect afterwards and influence where the locos ended up. This depends on the answer to my question of whether the wheels slid or rotated against the brakes, since one would result in wheelflats and false flanges, and the other in brake blocks wearing and becoming less effective. The first would be obvious to investigators, the second perhaps less so. On reflection I think the wheels would still rotate, in which case the effective coefficient of friction might be less than 10%. It is possible the fire damaged the handbrake on the loco concerned, but we don't know anything about this. Indeed I don't think the use or otherwise of loco handbrakes in this incident has been mentioned in any of the linked articles.

Going by these figures the total weight of the train is 9669+500, 10100 tons to make the maths a bit easier. The force needed to hold a train on a gradient is given by the weight of the train multiplied by the gradient as a fraction, or divided by the gradient as a "1 in". For an 10600 ton train on a 1% gradient this is 101 tons. If the coefficient of friction between wheel and rail is 10% this force could be provided by 1010 tons of the train being braked, assuming the brakes are applied hard enough for the coefficient of friction to be the limiting factor (ie wheels slide along the rails rather than turning against the brake blocks). This back-of-an-envelope calculation suggests that 11 wagon handbrakes on their own would be sufficient but probably not allow enough margin for safety. Applying the loco handbrakes as well would give nearly a factor of two safety margin. Anyone please say so if you think I am missing something in this calculation!

This has already been covered. The brakes are failsafe in the sense that they will stop the train if the pipe is vented, but the brakes are held applied by air from the reservoirs and if no air supply is available these will leak off after a period of usually hours.

Just to be clear, if the air brake was applied on the train, then there would have been no pressure in the train air pipe. So, regardless of whether the loco compressor was running, the train brakes would have leaked off over time. The only brake that is affected by the engine shut-down is the air brake on the loco itself, and possibly the air brake on the coupled locos if these were also linked by a second (reservoir) pipe (I think it is US/Canadian practice to do this). However, given that the consist of locos is able to start the train on the steepest gradient, the air brakes on the same locos on would usually be enough on their own to hold the train on the same incline. Certainly if insufficient wagon handbrakes were applied the leaking off of loco air brakes could well make the difference between the train staying in place and rolling away. What happens with loco parking brakes? Do these apply on all wheels like the loco air brake? If so these could possibly also have held the whole train. An air brake in good condition will stay applied for several hour before leaking off, and days is not impossible. However if the equipment is in less good condition it could leak off within an hour or so, which I think is the sort of time after which the train must be secured by other means. Given what we hear about this operation I'd say it was quite likely that the leaking-off time would be close to the minimum.

The HS2 design is in fact at a very early stage. Phase 1 is being worked up to a level sufficient to support a Hybrid Bill but even if all powers and funding were in place there would be several more years of design work before it would be "shovel ready". As such it is entirely appropriate that a large amount of contingency is declared and the surprise is more that it wasn't included in the original figures. Remember how Crossrail found about £2bn of savings on a £16bn programme at the time of the 2010 spending review? Some of this was from re-planning the programme to adopt a cheaper construction sequence at the cost of a delay to opening, but I suspect a lot was the release of contingency no longer required as the design got more detailed. That was a drop of around 10% of the project value for a project which was at the time about two years past the stage of getting powers, and some seven years away from opening.

Thanks Mike - the Pan Am rulebook linked from here a couple of pages back required a procedure very similar to your first alternative.

I would think not only is it unseemly but also unwise. By saying this he would appear to have admitted legal liability on behalf of the company, since the employee was an agent of the company and if he indeed failed to apply the handbrakes (I'm not speculating on whether that is so) there are highly likely to be underlying causes for which others in the company are responsible. For example was enough time allowed and was the training up to scratch? At the same time he is throwing away any remaining shred of good reputation that the company might have retained if he had stood up and taken it on the chin.

I agree but only up to a point. This accident will probably skew the statistics to the extent that the railways of North America will have more fatalities this year than the railways of Europe, despite the latter having much higher density of people and trains and a lot more passengers. That doesn't happen every year, though I've just Googled a statistic that around 700 people per year die at grade crossings in the States. Putting these figures together does perhaps suggest that the risks inherent in running large trains (often of hazardous materials) through difficult terrain warrant the same level of safety procedures, equipment and culture as running fast and frequent passenger operations.

The very useful rule book link posted by highpeak confirms that railroads are fully aware of the risk of air brakes leaking off and therefore enough handbrakes must be applied to keep the train from running away. If a similar procedure was in force on the road in question then the question of why the engine shut down and the air brakes leaked off is no more than secondary - the train should have been secured by handbrakes whatever the air brakes were doing. On that basis the conclusion has got to be that either the procedure wasn't followed, with too few or no handbrakes being applied, or that the handbrakes were somehow interfered with after the crew had left.

The brakes are failsafe in the sense that they will come on if the pipe is vented, and hold the train for at least an hour. However if there is no source of compressed air the system will leak off and become ineffective, so if a train is left unattended some other sort of brake must be used.

How long does it take to pressurise all the reservoirs on a long train? I wonder if the reason to leave the engine running was just to avoid having to do this in the morning, but in my view it still doesn't remove the need to apply enough other brakes.

If the engine was running that would provide air on the loco(s), but if the train air brakes were applied the pressure in the single train pipe would be low. Hence there would be no air to recharge the wagon brake reservoirs and the wagon brakes would leak off regardless of what the loco was doing. If all was in order the locos would provide enough air braking to hold the train, but this would be lost some time after the engine shut down. But surely it's one of the first rules of railway operating never to leave a train unattended on the air brake? There are all sorts of reasons why it might leak off if not monitored by the crew. The train should have been secured by means of loco parking brakes and/or wagon hand brakes.

At the other end of the tunnel they were headless as well.

My grandfather apparently ran a garage on Ducie Street* until he was called up for WW2 - I can't see any sign of it on this thread so far but would be interested if anyone has any info/pictures. *Family history could possibly be confusing with Great Ducie Street, round the back of Victoria.

The summary linked by 47708 does refer to speeding up Aberdeen trains by diverting some onto this route from via Fife, which would potentially reduce usage of the Tay Bridge. However I can't see that an Edinburgh-Aberdeen train would be noticeably quicker by this route, as it doesn't look much shorter. There could also be capacity issues on the single line out of Perth towards Dundee. Another concern would be capacity out of Edinburgh. Trains via all routes would still have to use the double track via the Forth Bridge, so there is a risk that diverting some trains via Glenfarg would reduce the fast service on the existing route.

There will be some trains between Manchester/Leeds and Birmingham which won't touch the busiest part of HS2, which is between London and the junction where it splits for central Birmingham and everywhere else. Despite this the sections north of Birmingham will be less intensively used than the section further south. There are various ideas floating around about using this capacity for other services, but they are not part of the current plans for HS2.

It does say somewhere that the terminal capacity is based on a turnaround of 30min, which squares with Mike's previous calculation and 11 platforms. Not considered, but perhaps worth thinking about, is that a Birmingham journey under an hour may be able to get away with a shorter turnaround (though the Scottish ones could be longer).

The issue at Paddington would be accommodating the 400m trains that will run on HS2 (2 coupled sets). This is the European standard for high speed routes and building for anything shorter would immediately reduce the passenger capacity in proportion. From Praed Street to the far end of the trainshed is only about 200m, so a high speed terminus here would involve widening and remodelling the throat (which may be too tight a curve for platforms in any case) or extending through the Lawn and under streets and hotels with the buffer stops underground somewhere near Sussex Gardens. The low-level station at Euston would also need 400m platforms but this probably just means they would be accessible from Euston at one end and St Pancras at the other. Shorter journey times will reduce the train fleet size, with savings in staffing and depot size, because a faster train can do more journeys in a day. They do of course increase energy costs. The alignment is mostly designed for 400km/h but reduces to lower speeds in various places where environmental constraints mean curves are too tight for this speed. This suggests that if there were other alignment constraints that would be more easily overcome at a lower top speed then the speed on that section would also have been reduced. The quoted journey times are based on an Alstom AGV with maximum speed of 360km/h but assumed to run at only 330km/h when on time (where the infrastructure permits) to give some margin for recovery from delays. As to 9min time saving, this is getting on for 20% of the London-Birmingham HS2 time. Experience with routes such as the ECML suggests that a 10% reduction in journey time on a long distance train will lead to a 9% increase in demand. There may be an even greater benefit if journeys can be brought within the threshold of 3-4 hours where rail becomes competitive with air on journey time. This doesn't apply to Manchester and Leeds, which have virtually no London or Birmingham flights these days, but could be important for Scotland. So the consequences for demand, revenue and the benefits of reducing car and air journeys do depend quite strongly on maximum speed. Nobody can say now with any certainty what the optimal speed will be in ten or 20 years time. There is particular uncertainty on energy costs, which will affect not only the cost of running the service but also the attractiveness of other competing modes where energy forms a greater proportion of the total cost. There would be no reason not to use a lower speed if that proved to be the best balance between demand, operating cost and environmental issues, but if the route was designed for lower speeds it would be almost impossible to upgrade later.

The latest proposal for Euston has 11 high-speed and 13 conventional platforms. There are various documents regarding capacity, this one for example shows a minmum headway a shade over 2min and a capacity of 18 trains per hour. This is based on a normal maximum speed of 330km/h with 360km/h being used to recover from delays. The published end-to-end times are based on the same maximum speeds.

Martyn has posted the reason why a stopping train would cost two paths even if its top speed was the same as the non-stopping trains and the station had long accelerating/decelerating tracks with junction points that could be taken on the curve at that top speed. It isn't a problem at OOC because every train will stop, nor at Birmingham International because there is parallel running from the platforms into the branch junction, but it would be a problem for any station where neither of these apply. Strictly speaking you could have fewer than alternate trains calling but each train calling would have to wait there until just before the next one arrived. It would be great if a Calvert interchange could be made to work, though as I suggested above it would be more for journeys to/from the North than London, but I can't see it happening.

That wouldn't work either. The 395 equivalent would be significantly slower than the longer-distance trains, so would take up several high speed paths on the busiest part of the network. This is in addition to the issue I noted above, where every train stopping at a Bucks station uses up two through paths. Even if it had a frequent train service the benefits for Bucks of a station are themselves a bit limited, at least in respect of travel to London. Except for people who live very close to wherever any station would be, the extra time to access a less convenient station would outweigh the time saving on the relatively short journey to Euston.

You are in esteemed company in thinking this - the Roskill Commission in 1968 favoured a site about ten miles to the east. Google for "Cublington Airport" to find out what happened next...