TE
TechEcho
Home24h TopNewestBestAskShowJobs
GitHubTwitter
Home

TechEcho

A tech news platform built with Next.js, providing global tech news and discussions.

GitHubTwitter

Home

HomeNewestBestAskShowJobs

Resources

HackerNews APIOriginal HackerNewsNext.js

© 2025 TechEcho. All rights reserved.

APT tilting train: A laughing stock that changed the world

63 pointsby darrhiggsover 9 years ago

8 comments

hristovover 9 years ago
What this article left unsaid was that the project was started before the time of Margaret Thatcher but ended in production during Margaret Thatcher&#x27;s premiership. Margaret Thatcher is well known to oppose the public rails and all other kinds of public works. It would have been very easy and popular then to vilify any large public project as a boondoggle.<p>The result is that the English still use trains (because their large population requires them) but get to import their trains from France, Italy and Japan.
评论 #10762924 未加载
alblueover 9 years ago
The APT was rushed into service before it was ready and suffered from initial glitches which ultimately led to bad press killing it off.<p>On the other hand I use the descendent of the APT (the Virgin Pendelino) to commute into work and back. The tilting mechanism is really sublime and incredibly comfortable. It was ahead of its time.
评论 #10762551 未加载
评论 #10762372 未加载
hyperpalliumover 9 years ago
\tangent another solution is camber or cant, where the outer rail is higher, banking into the curve, as an aeroplane turns.<p>A problem is the beginning of a curve. If the straight simply becomes an arc of a circle, the lateral centrifugal force (see xkcd) goes instantaneously from 0 to maximum. One might think an Euler spiral, whose rate of turn increases linearly, would fix this; but now, although the lateral force increases linearly, the onset of change in force is instantaneous, and is felt as a jolt by passengers. Apparently it is possible to create turns giving a smooth ride, but requires sophisticated dynamic models that are presently beyond me.<p>I started making a game with very smoothly transitioning banked turns, but it&#x27;s a lot more complex than I thought! (Other games use tilting-like mechanisms, such as suspension, and the natural averaging over the four contact points of a car, but that&#x27;s not applicable to what I want to do). If anyone has some pointers, I&#x27;d love to hear them!<p>P.S. Re trains: Of course, another problem is that banked turns are &quot;static&quot;, the same for all trains regardless of velocity; whereas the &quot;dynamic&quot; tilting can adjust to current velocity, on-the-fly (in addition to smoothing out transitions). The rail camber&#x2F;cant can remain suited to the typical velocity of non-tilting trains using the same track.
评论 #10762498 未加载
radiowaveover 9 years ago
To some extent the tilting was a side-show. It was the hydrokinetic brakes which really allowed the train to travel faster while still meeting the stopping distances necessary for the conventional signalling used on the line.
评论 #10761928 未加载
RickHullover 9 years ago
Can&#x27;t you just camber the track rather than make the trains actively tilt? I suppose the camber could be problematic at very slow speeds.
评论 #10762324 未加载
评论 #10762274 未加载
Gibbon1over 9 years ago
&gt;In its brief life the APT, with its futuristic sloped front, was vilified as a waste of money - £47m in total - and mocked by the press.<p>When I read stuff like this, I want to kick people.
评论 #10763461 未加载
slashinkover 9 years ago
The Swedish developed train X2, launched 1990 in Sweden as X2000 is still in service and is using tilting technology to increase speed. It&#x27;s been running the most popular commuter line (Stockholm &lt;-&gt; Gothenburg) for 25 years at 200 km&#x2F;h. <a href="https:&#x2F;&#x2F;en.m.wikipedia.org&#x2F;wiki&#x2F;X_2000" rel="nofollow">https:&#x2F;&#x2F;en.m.wikipedia.org&#x2F;wiki&#x2F;X_2000</a><p>Sadly it&#x27;s replacements focuses on efficient brakes over tilting.
protomythover 9 years ago
Move fast and break stuff doesn&#x27;t work for infrastructure projects. If you cannot get good PR on day 1 then delay until you can.