DISCUSSI0NS ON COMPATABILITY BETWEEN
BRISTOL AND BATH TRAMWAY SYSTEMS
2 December 2002
Brian Lomas and Adrian Tuddenham of 'Trams for Bath' visited the Bristol tramway planning office at Wilder House in Bristol, 2 December 2002. They met Andy Spearman and were introduced to Bob Fowler.
A considerable amount of 'archive' material from the early days of Bristol tramway planning was currently being turfed out. It was suggested that it could advantageously be passed on to B&NES as it would save the duplication of a lot of preliminary investigation work.
AS, BL & AT then walked to the offices of 'Trafic and Parking Consultants Ltd.', who are doing the preliminary planning work on the southern end of the new tramway Route 1 in preparation for the Transport & Works Act application. BL & AT were introduced to Graham Fincham and Andy Frazer who demonstrated some of the work in progress.
Currently the positioning of the track and platforms through the City Centre and dockside/business area is being drawn up. Surprisingly little change to the existing street layout and traffic flow is planned, but the probable needs of the tramway have been known for many years and any recent highways works have tried to take account of them,. This is an important factor for easing the amount of extra work and upheaval when the tramway details are eventually finalised.
The type of vehicle will not be decided for some time and so AF is basing his work on a 'generic' vehicle specification based on diagrams in 'Railway Safety principles and Guidance (HMRI)'.
The general guidelines are:
Minimum curve radius on street - 25m
Vehicle width - 2.650m
Max width on straight (includes 300mm clearance) - 3.7m
Max width on curves (includes 300mm clearance) - 4.3m
Wire height 5.3m
Currently there are no points of restricted headroom on the Bristol system
These are the guidelines TfB will need to follow on sections of Bath track which we want to be compatible with Bristol vehicles. They do not prevent the use of narrower vehicles and track widths if these would offer a significant advantage in the streets of Bath where compatibility with Bristol is not required. Bath still has the option of double-decked vehicles if the advantages which these offer are found to be worthwhile.
1) It appears that any vehicle suitable for the TfB Bath system will be able to travel around the Bristol system.
2) It appears that any Bristol vehicle will be able to travel into Bath at least as far as Kingsmead Square and will also have access to the Hospitals/Upper Weston route. It may be possible to avoid curve radii less than 25m in the City Centre Circle and on many suburban routes, further increasing Bristol vehicle accessibility.
If the City Centre Circle cannot be made accessible, there would be a strong case for using the Western Riverside as the main Bath/Bristol interchange point.
3) In order to use the same platforms, the Bath vehicles will either need to be exactly the same width (to door sills) as the Bristol ones or significantly narrower so as to allow interlaced track to give gap-free boarding for both types at shared stops.