To: The Editor (for publication)
11 November 2020
I am pleased that Peter Fox (letter – 5th November) thinks trams are great. They have the potential to provide an efficient, non-polluting public transport system that can carry large numbers of passengers and get people out of their cars.
The issue of cost is of course an important one, and the promoters of a tramway system must do their sums and come up with a reasonable estimate. In doing so, they will make due allowance for unforeseen difficulties like finding unexpected ground conditions, archaeology etc such as Mr Fox mentions. The constructors of the tram in Sheffield, for example, had to relocate a large number of graves which lay in the path of the tramway close to the Cathedral. These hazards may be unforeseen, but an allowance can be made in the cost estimates, and indeed the Department for Transport insists on an “optimism bias” of 60 per cent being added to any cost estimates before assessing the value-for-money of a proposed scheme.
Mr Fox mentions underground utilities (water, gas, electricity and so on) and the difficulty of carrying out repairs once a tramway is built. It is indeed a problem, and that is why the construction of all modern tramways has included the diversion of utilities away from the tram tracks to avoid having to close the tramway and dig up the tracks every time a fault has to be repaired. It adds a lot to the cost – in the region of 15-20 per cent – and the bulk of the extra cost falls on the tramway constructor even though the utilities end up with renewed equipment as a result.
A Briefing Paper by the industry body UKTram (www.uktram.com/documents/) in 2012 estimated the overall cost of a tramway at around £15 to £20 million per kilometre; adding an allowance for inflation means that a tramway today would cost around £25 m/km, depending of course on the route chosen, the type of terrain and many other factors. Recent tramways in the UK, such as Nottingham and extensions in Manchester, are in this ballpark. The tramway in Edinburgh was bedevilled by contractual problems which resulted in increased cost, so Nottingham is a better guide to the cost of a typical urban tramway. There are some designs for low-cost tramways which might lower this figure somewhat, but they are still being tested.
It is of course necessary to set the costs of a new tramway against the likely patronage and revenue which a system could attract., including other benefits such as reduction in traffic congestion in the equation. In this respect, Bath has some important advantages; it is a tourist centre, and the topography of the surrounding hills concentrates the passenger flows into fewer busy corridors than in a level city such as York. This helps the case for public transport investment.
(Dr) David Walmsley, BSc PhD CMILT MCIHT
Tram installation that cuts costs
Peter Fox in his letter in November 5th makes some excellent points about trams. However, the Edinburgh tram is but one example of how a tramway can be accomplished, and the worst-case cost example does not need to be adopted as a standard
Utilising the DFBOM project format (design/finance/build/operate/maintain) as opposed to the more costly, inefficient, and time consuming DBB format (design/ bid/build), my delivery team has been able to install tramways internationally for little as $16m (around Pounds 12/mile) per kilometre to ($25/mile- around Pounds 19m/mile).
That is inclusive of infrastructure and rolling stock. Our unique electric trams are self powered and do not require wayside power systems of any kind.
This not only eliminates costly overhead catenary systems (or wayside charging stations) but also eliminates the need to design and build track isolation schemes because the track is not electrified
The foregoing costs are achieved utilising the highest quality rail on steel cross-ties in a continuously reinforced 10 inch deep concrete track-slab.
Thus, our total costs are likely less than half that of conventional tram installs in cities such as Nottingham, nevertheless even these expensive methods make financially viable tram systems. Our system simply makes the economics even better
In existing city streets there are unavoidable contingencies due to site-specific sub-grade conditions concerning city utilities, but creative design solutions such as grade-beam bridges and access vaults with manhole access can be utilised to minimise utilities relocation and financial impacts.