The first stage of the British Rail Freightliner
network was virtually completed in mid-summer
1967 and plans were then prepared for the next
stage of the development. Market research had
shown that a second terminal would be required
in Manchester and that it would need to be a
major terminal using Goliath cranes spanning
six railway tracks.
The only railway site available with suitable
connections in the area was at Trafford Park
adjacent to a motive power depot which was to be
closed. Existing road access to the site, however,
was very poor and it could not be improved
because of the position of the Manchester United
F.C. ground and adjoining industrial premises.
The solution was to construct a completely new
access to the site from Westinghouse Road on
the other side of the Bridgewater Canal. The
scheme entailed the building of a bridge over the
canal and the demolition of some premises of the
Springfield Warehouse Company through which
the northern approach to the bridge would pass.
The design of the bridge presented no great
difficulties; the span, 61ft between bearings, is
moderate and the skew, 17° 30´, not large. A
simply supported welded steel plate girder
bridge on piled concrete abutments was therefore
decided upon. The question of maintenance
naturally had to be considered and, in view of
the limited headroom of little more than 12ft
above water level, it was felt by the Chief Civil
Engineer, London Midland Region, British
30 NSC
May 19
Railways Board, that here was an excellent
opportunity to gain experience of using a
corrosion resistant, or weathering, steel. Such
steels had successfully been welded for a number
of bridgeworks in North America but there was
no knowledge of their behaviour in this country
and, although it was intended to use Cor-ten B
steel produced under licence in Great Britain
to the specification of the United States Steel
Corporation it was considered desirable to call
for welding tests before making a firm decision
to order it. Consequently, the BCSA arranged
for comprehensive tests to be carried out by the
Welding Institute (formerly the BWRA). The
results of these tests having proved satisfactory,
British Rail decided to have the bridge at
Trafford fabricated in Cor-ten B steel and the
necessary materials were ordered.
The bridge consists of seven welded plate girders,
63ft long at 5ft centres, with 24in × 9in welded
I-section diaphragms of ½in plate flush with
the top flanges. Each girder. 2ft 8in deep, is
fabricated from a web plate 29¾in deep and ½in
thick, a top flange plate 12in × ¾in and a bottom
flange comprising a plate 11in × ¾in welded
under another 12in × ¾in plate. The total weight
of Cor-ten B steel is 33 tons.
Stud shear connectors welded to the top
flanges of both girders and diaphragms ensure
composite action with the 8in thick concrete
deck slab which is surmounted by a bituminous
waterproofing membrane protected by a layer
of quarry tiles and an asphalt wearing surface
laid with a camber of 3in to both sides of the 24ft
wide carriageway. An initial camber built into
the plate girders provides for longitudinal falls
from the centre of the bridge. The girders were
welded up complete with diaphragm brackets,
stiffeners and shear connectors in the shop,
where a complete trial assembly of the steelwork
was made before delivering all the components
to the site. All welds are ¼in fillets and all site
connections are made with 7/8 in diameter high
tensile bolts in 15/16 in diameter holes. The bolts
and washers are zinc plated and the nuts are
cadmium plated. Site erection was carried out
with the aid of a mobile crane.
The bridge and the associated roadworks are due
for completion in May 1969 and the Freightliner
terminal is expected to commence operating in
August 1969.
The design of the bridge was carried out by the
chief Civil Engineer, London Midland Region,
British Railways Board, whose permission to
publish this article is gratefully acknowledged.
L5i0s tYienagrss Ago
Reprinted from Volume 5 No. 4
June 1969
First British
Rail bridge in
weathering steel
Trial assembly in shop.
Construction of bridge after steelwork erection