Edwin_m

(2) is difficult. It took ages to get DfT to approve something as simple as a No Entry with an "Except Trams" plate on Metrolink, when the alternatives was the blue "tram only" sign which I suspect 90% of motorists wouldn't understand.

Referring this and earlier comments, recent developments on the south bank of the Trent are raised up above ground level, most by adding earth but a doctors' surgery is on stilts with parking underneath. Some, but not all, older houses in the area are similarly elevated. There are also various ponds, which I suspect are required to maintain the capacity to take up flood water despite the rest of the ground being raised. This is despite that part of the Trent having flood walls which were enhanced a few years ago, and never flooding in the big floods of 2000 though it flooded in 1948.

There were several single lead junction accidents, including Newton and Bellgrove in the Glasgow suburbs. Single leads have largely gone out of fashion, partly for safety reasons and partly because of capacity - to minimise conflicts on a flat junction you need to timetable trains on the same route in opposite directions to pass on the junction, which they can't do if there's only one track. A single lead and a double lead junction (with a crossover) both need four switches, so it's not obvious that the former saves much money, though it is probably less maintenance than a traditional double junction with a diamond.

There's a system of giant concrete "lego bricks" that are used for building things like railway bridge abutments and retaining walls.

I've spent an inordinate time putting together five of these in their later timber carrier conversion guise. About the same number of decals, at least one of which I'm becoming convinced doesn't actually exist on the sheet like the Emperor's new clothes, I'm just imagining putting it in approximately the right place.

I think it went up to 40mph a few years ago.

IT was a big issue when it first came in on schemes like Edinburgh-Glasgow, and caught a few people out. But I think the industry has now got its collective head round the possibility of doing whatever is reasonably practicable and justifying by risk assessment that it's unreasonable to meet the standard in full. The Cardiff solution also involved surge arrestors to deal with any overvoltage, which would probably be caused by lightning strike. I assume the logic here is that if the worst case voltage can be kept closer to 25kV, the clearance needed isn't so great. There is also the Steventon solution, accepting a steeper wire gradient than normal at the cost of increased wire wear and possibly a speed restriction for electrics, but as you say they all stop anyway (the non-stop Master Cutler finished a few years ago). And the bit of the platform closest to the bridge isn't normally used anyway, so can possibly be cut back and fenced off (the standard relates to straight-line distance from the wire or live pantographs to anywhere someone might be standing). With a combination of these measures I think there's a good possibility to find a reasonable solution.

I expect the reason to finish at South Wigston is that there are ideas for re-modelling the section from there through Leicester to Syston, to reinstate the fourth track and possibly provide a grade separation to remove conflict between the MML and east-west (mainly freight) traffic. If they wire the existing layout it becomes that much more difficult and costly to change it. Possibly by the time they get to South Wigston that idea might have been firmed or or abandoned, so in theory they might just be able to continue to Leicester.

It's a bit different though. Adding more passenger capacity in the form of longer or more trains, as long as it doesn't hit performance, leaves the journey time unchanged. On a road, adding capacity temporarily reduces the journey time because it eliminates congestion. This causes people who previously didn't travel or used public transport to switch to car, so the journey time goes back to about what it was. It's perhaps a different way of saying the same thing. If you don't understand the material you need to allow greater margins of safety. Even with steel there were new construction techniques and, because they were new, nobody really knew how well they would stand up over time.

However, it's fairly well known in transport planning circles that if you build a bigger road you just end up encouraging more traffic. The congestion ends up just as bad as before, there is more pollution and the public transport alternative is less viable because fewer people are using it. This doesn't really happen with building railways because the number of trains is managed and if done properly that keeps it at a lever where everything still runs smoothly.

One or more upside down test units might make a good wagon load too? I suspect the swabs are the kind of plastic that's impervious to any sort of glue, paint or solvent.

Masonry bridges are generally over-engineered by definition. They use only compressive forces, and stone is immensely strong in compression. With some fairly minimal maintenance and as long as the supporting ground doesn't move, these can last almost indefinitely - there are many road bridges still around that predate the railway age. Unreinforced concrete bridges, such as those of "Concrete Bob" on the West Highland, are similar in structural behaviour to masonry. Not all Victorian bridges were over-engineered though - thinking of the cast iron ones in particular. Most of those aren't around today, simply because they proved to be inadequate or in some cases collapsed. Steel or reinforced concrete carry tension forces in various parts of the structure, and these are present in most bridges made of those materials. Thus the bridge has to be designed based on structural analysis, and this depends on the loads it has to carry. Thus they can become inadequate if the loads increase, or some unexpected deterioration reduces the strength of the material. The latter has happened to many reinforced concrete bridges from the middle of the 20th century, when use in tension was fairly new and long-term behaviour wasn't well understood. Hopefully we know a bit better these days!

Didn't fitment of AWS effectively make them unnecessary? Having said that I'm not sure AWS got to all the more obscure routes until sometime in the 1990s. I don't believe they were ever considered necessary at colour light distants either.

I seem to remember extra extraction fans were also fitted in those smoking areas. Struck me as a big expense when I think they were abolished only a couple of years later. These were, I think, the last smoking accommodating on the UK rail network.

The business case for HS2 identifies a range of benefits, which are mainly to the wider economy rather than narrowly on the financial performance of HS2. So I agree there should be a followup study to determine what actually happened and whether it agreed with the forecasts. This is of course not straightforward. It's always very difficult to separate the effects in a real society where you can't do the "controlled experiment" of changing one thing and keeping everything else the same. Since the business case there have been two unforeseen major blows to the economy, Brexit and the pandemic.

Probably because Heathrow was needed first. The Heathrow Express 332 units and the tunnel were fitted with GW ATP, but the replacement 387 units weren't. They were supplied ready for fitting ERTMS but fitting the old system would have been very difficult. Just using TPWS instead was deemed an unacceptable reduction in safety levels, so they fitted the new units and the tunnel with ERTMS. I'm not totally clear why the same argument didn't apply to the line between Paddington and Airport Junction - perhaps as a non-tunnel route the risks were just lower?

We can't know this, but construction is well under way over most of the route of HS2 London to Birmingham so it is possible to get something started eventually. As to rail freight, coal has largely disappeared but intermodal traffic has increased, including the likes of Tesco doing trunk hauls between distribution depots in England and Scotland. This tends to be long-distance, so the total tonne-kilometres of freight hasn't changed that much. Shorter distance goods still goes by road, but a fairly small change in circumstances (such as gauge clearance to Southampton a few years ago) can lead to the break-even point moving and a quite big increase in rail freight assuming the relevant capacity is available. Gauge and capacity enhancement could produce something similar for Transpennine, although as distances are shorter than Midlands to Scotland it's not a certainty that the economics will work out. Another development is at least two companies converting surplus EMUs to carry parcels traffic - not yet proven viable but one to watch. Coal traffic was unsurprisingly between coal mines or ports and power stations, so didn't overlap much with the trunk passenger routes, and providing alternative routes for passenger trains would only have allowed extra coal traffic in a few places. Intermodal tends to run to major centres of population, so has much more need to use the same routes as intercity passenger, and should benefit that much more from capacity released by high speed lines.

The one in the middle is quite camouflaged too.

Indeed it did, pending a review of options for Leeds.

I'm probably guilty of oversimplifying here. Sometimes multiple options are made public, but in the case of EWR they were no more than shaded areas on maps showing that the option would run somewhere through the shaded area. And when they got specific, they managed to score a massive own goal with Bedford. As of just now, HS2 north of Sheffield is still shown on their interactive map and the plans are still on gov.uk. How long it remains there is another question. https://www.hs2.org.uk/in-your-area/map/#11/53.2597/-1.2397/filter=hs2-stations,hs2-network https://www.gov.uk/government/collections/hs2-phase-2b-crewe-to-manchester-and-the-west-midlands-to-leeds#west-midlands-to-leeds-route-maps At the risk of going off-topic again, I'm aware that a Manchester-Marsden-Bradford option was being talked about a year or two back as a means of serving both Bradford and Huddersfield, so I would expect early stage plans for Manchester-Marsden to exist already.

Options will have been looked at and design work done on some of them, to a level to establish feasibility and an approximate estimate of costs. But at this stage of a study these are kept strictly confidential, otherwise if they were released people would start claiming property blight when one of the routes impacted on their houses etc. This might end up costing the taxpayer large sums, much of it for options that weren't ultimately taken up. If properties were purchased then they might end up being sold again and the money recovered, but not the amount spent by the project in undertaking the purchase and sale. Normally options are whittled down to a preferred route, which is published prior to consultation and arrangements for compensation for property blight brought in at the same time.

Nottingham and Derby are about as far from London as Birmingham is, and I don't think anyone questions that Birmingham should be a primary HS2 destination (other than those that question HS2 as a whole). Nottingham to Birmingham is a further than Manchester to Leeds, and I don't think anyone questions that should be a primary NPR route (other than those that question NPR as a whole). So I don't think these journeys can be described as too short for high speed. Nor are they as fast today as many journeys that are replaced by high speed in the original plans. From London you can be in Warrington or York in a similar time to Nottingham or Derby, . I'd be interested in a source for your Nottingham vs Derby to London figures - certainly before Covid Nottingham had the same number and similar length of trains to Derby and Sheffield combined, suggesting the number of passengers was in a similar ratio. I can only think it's because many people in the Nottingham area with access to a car will drive to Grantham for a faster service.

There's also a nasty reverse curve going round a hill just east of the eastern portal, which would probably impose a speed restriction compared to the straighter alignment further east. So I'd expect it to tunnel through that hill, and if it was me* I'd put the junction about where Ordance Survey shows Slaithwaite Hall. Depending on the topography and the alignment needed to head towards Manchester, there might even be a very short surface section crossing the Colne Valley near the existing portal. *I've been involved in high speed line design projects, but have no inside knowledge on this one.

I think they were talking about the east portal of Standedge, not the west. Neither the Micklehurst Loop nor the route via Lees nor any other existing/disused route in the area would offer any journey time benefit.

They may be equivalent to London but there are other places to travel to, and which will benefit from HS2. Nottingham to Birmingham is over an hour, including several minutes reversing in Derby, and will be less than half that if HS2 is built as proposed in the IRP. Derby to Birmingham has twice as many trains (in non-Covid-times), including some that skip the stops that Nottingham trains make.