For the first time this week, I travelled on the Elizabeth Line; a completely magnificent experience. The London Underground celebrates its 160th year this year, and there is still plenty of evidence on some lines of the original mid-Victorian infrastructure. In my youth I used to explore the network at weekends, the iconic Underground map making navigation very easy. Parts of the system in Central London are very deep, and some of the linking pedestrian tunnels were and are still quite claustrophobic—narrow, with low ceilings. Not infrequently, I used to find myself quite alone for minutes at a time. I would sometimes wonder if I had taken a wrong turning and ended up in the dungeons of some magic castle inhabited by the Nibelungs or some other race from the underworld.
The Elizabeth Line is the absolute antithesis of the early system, positively cathedral like in the scale of the stations and pedestrian access tunnels; in fact the tunnels are so wide and high that the word ‘tunnel’ hardly seems appropriate. For all that the Crossrail price tag was nearly £20 billion, the design drips premium quality and attention to detail. Of course it will irritate other parts of the country struggling to get any sort of train service. But despite the concerted efforts of successive recent governments to make visitors to this country quite unwelcome, London remains an enormous pull for tourists. The Underground network was operating at saturation point; the Elizabeth Line has increased the capacity of the London railway system by 10%. Even so, it was standing room only yesterday. But they still can’t get the escalators right! I remember the early escalators with their wooden steps, each one having multiple strips of wood, all individually screwed on. The parallel strips provided the grooves in which ran the prongs of metal forks at the top of the stairway designed to prevents shoes etc. becoming caught up in the mechanism. The new escalators are all metal; the grooves are smaller and greater in number and the forks are also quite small. The handrail moves at the same rate as the stairs, or is supposed to do so. In fact, even on the brand new and very long escalators at Liverpool Street and Tottenham Court Road, the handrails move slightly faster than the stairs—as they do on every escalator on the network that I have encountered. It is possible that the issue is one of gear ratios; gears do not yield to the decimal system. They are digital, or perhaps one ought to say dental, in that they must have an integral number of teeth... This means that only specific ratios can be achieved, thus making it impossible to match rotational speeds exactly; I presume this is the root of the problem. I have contacted an escalator manufacturer for an answer to this conundrum, but I am not holding my breath.
4 Comments
Paul Robertson
14/4/2023 03:13:54 pm
If it's any consolation, I have noticed the same 'conundrum' on the Paris métro, but I admit to not having gone to the trouble of observing whether or not the rail is *always* faster than the stairs - ascending or descending - only to the trouble of noticing that it was wrong. I doubt if even one person in ten detects the disparity, let alone comments on it. However, we of an analytical bent, shall not let the marrer lie. I am currently in Marks and Spencer, Braehead where there is a system of escalators. I shall of course keep you informed.
Reply
Roger Pittock
17/4/2023 05:29:23 am
Were you going up or down? I guess up. Did you notice the speed differential near the top or bottom? And were many on it at the time? My theory is handrail elasticity. It's got to be driven from below and, on the way up, forces pulling at it get less as you near the top - so it recoils as you get nearer to the top giving you the impression it's going faster. If I'm right it will seem to be going a little slower nearer the bottom - but of course you'll be acclimatising then so be less likely to realise it.
Reply
Peter Maggs
17/4/2023 07:22:21 am
It's a good theory Roger. From impressions over a number of years, the effect is largely unchanged whether going up or down, near the top or bottom, and regardless of the length of the escalator. In fact Googling the question (which I should have done before writing the post) reveals some interesting answers: This from the Guardian Newspaper, date unknown:
Reply
Roger Pittock
17/4/2023 01:12:53 pm
The first answer - distance to travel - is poppycock! Provided the drive wheel(s) is/are on the straight part of the escalator, the linear speeds of both will be defined solely by the ratio of the sizes (if pinch wheels) or teeth count ratios(if rack and pinions). Leave a Reply. |
AuthorWelcome to the Mirli Books blog written by Peter Maggs Archives
December 2024
Categories |