Olton to Lapworth - Quadrupling Birmingham Main Line

GWR Route: Banbury to Wolverhampton

Extract from Great Western Railway Development Works (Published December 1933)

Before the war the Great Western had a scheme for providing four running lines out from Birmingham (Snow Hill) as far as Rowington Junction, where a branch to Henley–in-Arden left the main line. The construction of the direct line between Tyseley and Henley-in-Arden, as well as changed conditions resulting from the war, however, caused the widening works to be carried out only as far as Olton, 5 miles from Snow Hill. The development of traffic, past and prospective, made it desirable to continue the quadrupling as soon as a favourable opportunity occurred, and when the Government facilities under the 1929 Act became available, the work, as shown in diagram form was put in hand.

As completed there are now four lines all the way from Birmingham to Lapworth, a distance of 12¾ miles. The abandonment of the Rowington Junction – Henley-in-Arden branch, owing to the removal of the rails for war purposes and the diversion of the local traffic to the roads, has made the extension of the two additional lines beyond Lapworth unnecessary for the time being.

The work has involved about 450,000 cubic yards of cutting and embankment as well as the construction of 33 bridges and five stations. Steam and petrol-driven excavators were used, and all excavation shifted by Decauville railway. Between the main and relief lines high speed junctions with switch diamonds have been laid at Lapworth, Knowle and Solihull. No curves have a radius smaller than 1 mile, except at one spot in the relief line at Knowle and another at Olton, where the radius is 60 chains.

The permanent way is of the usual standard 95-lb bull-headed rail in 60 foot lengths resting on cast-iron chairs weighing 46lb each on creosoted Oregon pine sleepers. A 12 inch layer of clinker ashes was laid throughout upon the formation, and above this top ballast of crushed stone was used. The formation in cutting is drained by means of stoneware pipes, varying in size from 6 to 12 inch diameter and laid along both sides at the toe of the batter. A 6 inch pipe has been laid in the 6 foot way through the stations between the platforms. All the pipes are, of course, open jointed with catchpits at suitable intervals.

The principal bridge on the work is a large steel underbridge at Warwick Road, Olton. Owing to the road being widened from 38 feet to 60 feet it was necessary to have five girders of 152 feet span. These are of the open lattice type with parallel booms 175 feet long overall and 20 feet high, and each weighs about 160 tons. The floor is of steel plate and cross girders and rail bearers and the whole contains nearly 1,000 tons of steel. Cross bracing is provided between the tops of the girders. The abutments are of mass concrete reinforced in places with old steel rails. There are ten brick arches on the work, and the whole of the masonry is in lime mortar. The face brickwork in all cases is of Staffordshire brindle brick.

The five stations situated on the widened length have all been either entirely rebuilt or extensively remodelled. At Olton and Solihull the old stations were demolished, and the new station buildings are below the level of the line and are connected to the two island platforms by means of subways. At Widney Manor, Knowle and Dorridge, and Lapworth the station offices are at rail level, and the platforms, on which the usual waiting rooms, etc, have been provided, are connected by means of footbridges. All platforms are covered with umbrella roofing, covered with Robertson's corrugated steel sheeting.

Provision has been made for the Knowle racehorse traffic by a loading platform for 14 horse-boxes, as part of the up main platform. Carriage sidings have been laid out on the down side of the line. At Knowle a new goods yard has been provided about a quarter of a mile on the Birmingham side of the passenger station. The goods shed is 120 feet x 40 feet and is steel framed and covered with Robertson's sheeting. A 1 ton travelling crane is provided for its entire length. At Solihull also a new goods yard was laid out with a similar goods shed. Ample cattle pens, roads and stacking space are provided both at Solihull and at Knowle. Except Widney Manor, where electric light is installed, the lighting of the stations is by gas.

All lines are track circuited throughout, and between Acocks Green and Solihull semi-automatic signalling has been installed. There are new signal boxes at Solihull and Olton, and where facing points are beyond the Ministry of Transport limitation of limit distance for manually-worked points they are electrically operated.

The following article has been transcribed on the tests undertaken on the bridges located between Olton and Solihull. This article is repeated on the Solihull Station page.

Bridge Tests on the Birmingham Main Line (from ‘The Railway Magazine’ June 1934 – J.D.H.)

On Sunday, March 25, a remarkable spectacle was afforded by the testing of steel underline bridges, on the recently completed quadrupling on the Olton – Lapworth section of the G.W.R. main line to Birmingham and the North. Four “King” class locomotives were used. Nos 6001, 6014, 6017 and 6005; the first two were coupled together without load, while the latter two double headed a train consisting of a third-class brake and a saloon, together weighting 45 tons. In testing a bridge carrying two tracks (one up and one down in normal working) the two pairs of locomotives first coasted across abreast at a speed of 2 m.p.h., or less, while the vertical deflections of the girders were measured. This was repeated twice , after which the locomotives ran back ¾ mile from the bridge, and stopped in line. All four then proceeded to accelerate in the up direction towards the bridge, with wide-open regulator and cut-off very late in the stroke.

The pairs of locomotives were drawn dead level as they approached the bridge, the exhausts rising quite 30 ft in the brilliant sunshine above each of the four chimneys, to the accompaniment of a deafening roar. The normal test conditions were 500 tons weight and 60 m.p.h.; in actual fact the four locomotives and tenders weighted 542 tons full, and in various runs speeds of 59 to 62 m.p.h. were attained, giving an acceleration from 0 to 62 m.p.h., which averaged almost exactly 1-foot-per-sec, - a phenomenal figure for steam locomotives. Even with so trifling a load. After passing the bridge the engines were stopped and returned to their starting point for a second run, the bridge deflections being measured each time. No 6001 alone was fitted with a working speedometer, of the type recently adopted.

The effect of the small load behind one pair of engines was a striking feature of the runs; some 20 yards in the first 200 yards of each run were lost by this pair, but they could, on the other hand, be brought to a stand in 150 yards less distance than could the unloaded pair, with the coach brakes operating in addition to those on the engines. Twelve runs in all were made at speed over the six double-track bridges tested on this date; on the same day Nos. 6001 and 6005 were used for two further tests of single-track bridges carrying the own relief lines only, the four tests runs being again made in the up direction. Railway enthusiasts from considerable distances, and other spectators also, might have been attracted had the fact been made public that these tests were to take place; as it was, the spectators who witnessed this sight of a lifetime numbered fewer than a score.