Last week I looked at the frequently failing escalators at North Melbourne Station, which raises the question – what is causing them to break down so often?
The main concourse at the city end of North Melbourne station opened to passengers in November 2009, and with it came eight brand new escalators to provide access to the six platforms beneath.
Combined with the existing ramps at the north end of the station, the new concourse provided an additional route for passengers to change platforms, as well as aiding access for the disabled by the provision of lifts to each platform. Two escalators and a lift serve each of platform 1, platform 2/3, platform 4/5 and platform 6, with additional staircases also connecting platforms 1 and 6 to the overhead concourse.
As mentioned in my previous post, I first noticed a defective escalator in October 2012, and since then I’ve seen a broken down escalator at North Melbourne at least 16 times – about once every two months.
| Escalator | 1A | 1B | 2 | 3 | 4 | 5 | 6A | 6B |
| Failures | 1 | 3 | 0 | 4 | 0 | 2 | 1 | 5 |
I have numbered the escalators 1A to 6B – east to west, based on platform number they serve.
Ever bought an escalator?
As with everything in this world, buying the right tool is important – there is no point spending thousands of dollars on something you will only use a couple of times a year, while it is also a waste of money to buy a cheap one that will break after a few hours of heavy use.
The same applies to escalators, with escalator manufacturer Thyssenkrupp dividing their range into three categories:
Commercial
Commercial applications are typically installed in department stores, shopping malls and office buildings. Commercial escalators are typically designed to move thousands of people and yet look elegant.Heavy Duty
Heavy traffic applications are typically found in convention centres and stadiums where there is a very high traffic volume. These heavy traffic escalators have increased chain and motor sizing.Transit
Transit applications are typically railway stations, airports and subway stations where there is a very high traffic volume. These transit escalators have a much larger, heavier truss structure, increased chain and motor sizing, heavier step track construction and a larger, heavier handrail drive system.
As you would expect, the designer of a building has to match the number and grade of escalators to the transportation task expected to be placed upon the completed structure – undersized escalators will break down, while oversized escalators are a needless cost for the client.
Back to North Melbourne
I had a closer look at the escalators at North Melbourne, which lead me to ThyssenKrupp – a major escalator manufacturer. After trawling through their data sheets I pinned them down as a ThyssenKrupp ‘Velino’.
Note that the ‘Velino’ is ThyssenKrupp’s commercial grade escalator – their bottom end model which was never meant to be used in a heavy traffic location such as North Melbourne station, where thousands of commuters walk up and down the escalators each day.
In the end, this suggests that the blame for the failing escalators goes all the way back to the design of the station – the level of passenger traffic was underestimated, leaving to undersized escalators being specified, which survived for the first few years, only to progressively fail as the components wear out prematurely.
Conspiracy theory
With my tinfoil hat on, I have an alternate theory – correctly sized escalators were specified as part of the North Melbourne station redevelopment project but the beancounter objected to the cost, leading to lower-specification escalators being substituted instead.
Bonus footnote
Platforms 2-3 and 4-5 have a curious escalator arrangement, with a ‘normal’ width escalator paired with a ‘narrow’ escalator that only just allows two people to pass each other.
The reason for this was the narrow platforms – if two normal escalators were installed on the platform, where would not have been enough room for wheelchairs to navigate between the escalators and the platform edge. Platforms 1 and 6 are much wider, so the same arrangement wasn’t required.
The beancounters probably just thought passengers could walk up and down faulty escalators.
Just like Laverton station – ambulance staff can carry bodies out via the tracks:
http://www.theage.com.au/victoria/state-election-2010/rail-lifts-revamp-to-take-stretchers-20101124-187ew.html
Excellent post as always. I think it’s very likely that cost cutting is to blame, apparently there was something similar at play with the decking of the new mezzanine which is why it has cracks in the surface.
Re escalators in general, what are your thoughts on overall width? Some escalators are wide enough to overtake a pram, some aren’t – is overtaking something to encourage or discourage?
I’ve noticed the cracking along the concourse – I wonder if it is just cosmetic due to the fancy concrete surface, or something worse.
As for overtaking people on escalators, metro’s latest round of posters look to be encouraging the practice.
Escalators specified for transportation projects
The Thyssenkrupp web page you linked to is clear that a key (but not the only) distinguishing characteristic of these elevator types is the rise. Commercial grade escalators have a maximum rise of 30 feet; heavy duty up to 65 feet; and transit up to about 164 feet. The difference in rise would go a long way to explaining the need for more heavier motors, chains, and trusses in the heavy duty and transit classes.
Given this characterisation, the North Melbourne escalators would be at the top end of the commercial grade, but would not appear to need the ‘transit’ grade.
As for the theoretical capacity – the brochures you linked to show that the Velino (commercial grade) has a capacity ranging from 6750 people per hour (800mm treads @ 0.5m/s) to 11700 people per hour (1000mm treads @ 0.65 m/s). The Victoria (transit grade) has exactly the same range.
It is clear from the description that a ‘transit’ escalator should be designed to have low downtime and short repair times. These are, of course, very important where there are only a few deep escalators servicing an underground station. It’s less clear that this is a critical issue where they are low rise escalators serving individual platforms.
I didn’t look into the relationship between escalator rise and the heavier design, but it is an important one – North Melbourne don’t fall into the same grade as Flagstaff and Parliament stations on that front.
Another thing I am yet to work out is how well lower grades of escalator handle a stampede of passengers running up or down them – are they only designed for users who stand still? I can imagine that someone running down an escalator to catch their train puts a *lot* more load on the tracks.
If you head to a shopping centre and watch the escalators, it is rare to see anyone walking up them, and even more rare to see someone running – most of the time they will have two people standing side by side.
A competent beancounter can easily identify that buying a cheaper product will not save money in the long run. If this was the case for businesses, cafes would buy cheaper consumer coffee machines to make coffee or a cleaning company would buy a cheap consumer grade vacuum cleaner. The opposite is true for most businesses with most of them buying the more expensive heavy duty commercial products as they will last longer and result in lower maintenance costs in the long in the run.
It seems that the decisions made were political as the government minister responsible for this situation is long gone.
What about the other newly redesigned RRL railway stations. Footscray, Sunshine etc. What grade/type of escalator have they installed at these stations. Is there a pattern.
At Footscray station they have escalators from SJEC – a Chinese company. Sunshine and the other RRL stations don’t have any escalators, just lifts.
You are amazing. To research to nth degree as you have done is just brilliant. Of course you already knew about the under specified escalators before you wrote the post about the failing escalators. Nevertheless, it does not detract from what you have posted.
I originally intended to publish it as one post, but the gallery of escalator failure took up so much space I decided to spin it off into a separate post. 😛