Recent content by Technologist

If we look at monthly rainfall about 50mm is typical in drier bits of the UK, if we needed to replicate this on 5% of the network to a width of 10m we would be looking about 400,000 tonnes. That would be about 130 fully loaded tanker trains per month. Sounds pretty doable

They are slightly more advanced than that as they are coming from the background of actually planning this route when they were in government and they also have a business model and enough name recognition that I knew who they were before they proposed it. They are flying a kite but they aren’t...

I think the intent is to either collect tolls or for the investors to get paid per vehicle usage. Actually it might be an interesting way to do fund roads. Work out a benefit per user for a bunch of schemes set a minimum BCR for these schemes, let developers bid against these schemes. Private...

I've listened to Michael Dnes being interviewed on this project on the YIMBY podcast. He lead the team that looked at the tunnels when he was a civil servant. Someone mentioned drill and blast at the time but the people they had hired didn't know much about it and everybody assumed TBMs so they...

Anyone who thinks that support for Sizewell C from an engineering feasibility perspective is a negative for someone's professional competence shouldn't really be listened to either. - Source I'm a nuclear engineer. Issues like costal erosion are absolute bread and butter for nuclear developers...

The whole premise of this thread is wrong, if you want to relieve an income distribution problem you achieve that by giving poor people money or by taxing them less. Trying to do it via anything else just results in distortion of markets and inefficiencies like paying someone’s fare that they...

Dream Cross Country Train: 9 car BEMU derived from off the shelf automotive componentry, transformer replaced by DC-DC converter. Carries 39 tonnes of batteries (6MWh) for a 150 mile range off wire at express speeds. It has 35MW (46,500bhp) from a pair of Lucid Air PM motors (32kg) per axle. It...

I am acknowledging that the crash may well have been around 40mph (that crash test was at 37mph), see previous arguments as to why I was surprised by the lower number and severity of casualties given the high speed of the crash and the fact nobody is secured. Whilst crashes are unpredictable if...

I will probably read that, I was coming at this from a perspective of if you crashed a car at 49mph into a stationary car without wearing a seatbelt you would be quite likely to suffer fatal injuries and the vehicles would be mashed. However I think the takeaways from here are: The crumple...

Very interesting: I would compare the activation of the crumple zones on the following carriages here vs what we see at Bedford and infer that the impact was likely at a lower velocity. Obviously the designs of the trains aren't the same and we had what might be termed "incompatibility" with...

I'm engineer, the worst possible bit of evidence is "if someone has said it it must be true" based on their reputation. I have no doubt that RAIB have a piece of telemetry that either ends at 49mph or a G meter reading that registers and impact when the rail vehicle was doing 49mph. I can think...

What's the sampling rate of the telemetry, were the sensors destroyed in the impact and the last few seconds were not yet written? As a basic sense check if you drove your car (an object designed to resist this impact) into a larger stationary car at 49mph what would the results look like? To...

That makes sense as an argument in the abstract, however at most stages of the HS2 project it would have been cheaper to cancel it and start again. There is relatively little evidence that HS2 itself has the capability to lower costs and run things efficiently just by keeping it going. Steven...

Moderator note: Split from https://www.railforums.co.uk/threads/report-of-collision-bedford-elstow-19-06-26.303537/ I think the estimated collision speed of 49mph needs to be taken with a pinch of salt, Euro NCAP tests cars at 40mph into a semi deformable barrier and they lose 10-20% of their...

How's it worse than todays system where a person demands to see a ticket? I'd actually argue the the existence of the system would actually be less intrusive as most passengers would just tab in and the system would notice that this had happened and not bother them. A small number of users...