I Agree With Matt L’s Analysis on our new EMUs

Matt L from Auckland Transport Blog wrote up a post on his self-analysis on the speeds of our new incoming Electric passenger trains. I agree with his post and thus endorse and/or recommend his post over at Transport Blog. My sole comment on his post at the moment is that for the Southern and Eastern Lines at least, slicing upwards of 7-minutes of the total journey time from Britomart to Papakura will be a good attractor to rail passengers on the rolling stock and speed side. However we still have infrastructure and customer service aspects to work on with our rail system (and Auckland Transport as well) but separate posts and debates for those.

So from Transport Blog – an intro to Matt’s post on the EMU speeds:

Source: Auckland Transport Blog

By Matt L, on January 16th, 2013

This year the first of our new electric trains will arrive and one of big benefits of them will be that they have faster acceleration than the clunky diesel trains we have now but the question is just how much faster they will be. For some reason it is something that Auckland Transport have been pretty reluctant to actually talk much about which I am guessing is due to them not wanting to get peoples expectations up. We however are not AT and are free to talk and speculate all we like so with that in mind, some time ago I built a model to try and work things out. I actually blogged about it back then but at the time I had only showed the western line, with this post I thought I would look at the whole network. Before I go into the results, for those that are interested, here is an explanation as to how I have worked the times out:

First I have worked out the distance between each station and for each leg of the journey I have assigned a maximum speed that the trains can travel and I have kept most of the network at 80kph with the inner sections at 60kph. When the EMUs were announced AT said that they would be able accelerate and brake at 1m/s². Based on that I then worked out how long, both in time and distance it would take to reach the top speed and slow back down again for each section of track. For those interested it takes 22 seconds and 247 metres to reach, or slow down from 80kph based on that acceleration of 1m/s². The next step was to work out how long the train would travel at top speed. To do that I subtracted the acceleration and braking distance off the distance between stations and worked long it would take. For each station I then added in a dwell time to represent how long it would spend on the platform. To be conservative i generally used 45 second however for busier stations I used 1 minute. I then added the time spent accelerating, braking, at top speed and the dwell time together. Lastly to try and be conservative I added in a multiplier of an extra 20% to account for things like slow drivers, corners and junctions which that then gave me an overall result for each station.

Here are the results verses the current times for each line, I have left out Te Mahia and Westfield as based on the draft RPTP they are likely to close, I have however added in the Parnell station. For the Western line I have added in the time allocated for the driver to change ends at Newmarket together with the travel time. You may also notice some of the times look longer than current. That is because AT obviously round the times up or down to get to an exact minute.

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You can read the rest including the graphics over at his post.

Just a note on station dwell times as it has been mentioned: 30 seconds is the official Station Dwell Time (the time a train is stopped at a station to exchange passengers) set by Auckland Transport for all intermediary stations (those between the origin station and final destination station) except for Western Line services at Newmarket in which the Dwell Time is 3-minutes to allow the driver to change ends. There are also Marked Stations as well (Otahuhu, Newmarket, New Lynn and Glen Innes being examples) in which a train can not depart from that station until that marked time – it shows as a BOLD time on your paper timetables for each line.

Excellent work Matt.