‘A car specially fitted with wheels to travel on the railway went up and down the Stour Valley line on Sunday, attracting many curious glances as it whirled along at speeds up to 40 miles an hour. This was not a glimpse of a new pattern of transport, but part of an elaborate advertising stunt. The Vauxhall Cresta car is being used by a petrol company that wants to prove that its particular brand of fuel is more economical in a car going on rails. TV FILM Test runs will go on for the next three Sundays and then the ‘real’ test will be filmed for a television commercial. The Stour Valley line has been commissioned by the company because it is normally closed on Sundays.  Haverhill is the focal point for the tests. Sunday’s runs, with a diesel unit in close pursuit in case of accidents, were reported to have gone smoothly. The car will be radio controlled and driverless for the film.’ ‘Haverhill Echo’ 12 January 1967

During 1966 Shell Mex were preparing to introduce a new petrol product.  The new product would give additional economies to road users.  It contained an additive which would be marketed as the ‘mileage ingredient’.

The company decided to prove the increased economy available from the new product by comparing the distance travelled by a family saloon running on a gallon of standard Shell petrol with the distance travelled on a gallon of Shell petrol with the ‘mileage ingredient’.

It would be necessary to test the two grades of petrol in identical circumstances to give the most accurate results.

The marketing department of Shell Mex decided to approach British Rail Eastern Region with a proposition.  They wanted to hire a section of railway line in order to carry out and film their tests using a car fitted with rail wheels.  Unlike the road, the gradients on a railway line were negligible, the car would always follow an identical course and have a clear way ahead.

The region was, at the time, still contracting and losing money as a result of the Beeching Report.  It was seen as good business sense to accommodate Shell’s request if possible.

The Stour Valley line was chosen because it was closed to traffic on Sundays between Shelford and Sudbury.  Freight traffic had ceased on 31 October 1966, but the Goods Yards and their connections remained in situ for stabling/testing purposes.  Signalling Inspector Debenham of Cambridge was summoned to headquarters and tasked with making the necessary operating arrangements to enable the tests to take place safely.

Inspector Debenham set about drafting a set of Special Instructions for the Signalmen and Crossing Keepers, while Shell Mex acquired a brand new Vauxhall Cresta, fitting it with radio control equipment and a glass petrol tank within the passenger accommodation for greater consumer impact in the filming.

The tests were originally due to take place between Sunday 27 November and Sunday 18 December 1966.  They were, however, postponed and the car was eventually delivered to Haverhill Goods Yard, fitted with rail wheels, and placed on the rails on Thursday 5 January 1967 to enable static testing to take place.  It was permissible for the car to move within the sidings, but no movement onto the single line was permitted without Inspector Debenham’s authority. 

On the following Sunday (8 January 1967), Shelford, Linton and Haverhill signal boxes were opened at 07.30 for the passage of a DMU, 07.30 ECS from Cambridge to Haverhill.  The car was coupled to the Sudbury end of the DMU in Haverhill Goods Yard and hauled back into the Linton/Shelford section.

Taken at Haverhill North. Cambridge Newspapers

Meanwhile all signal boxes and crossings between Haverhill and Chappel were opened at 09.00.  Country Club Crossing at Clare was also manned as, although this was a user worked crossing, it saw heavier use than most.  The crossing keeper was provided with a ‘walkie-talkie’ radio in order to communicate with his colleague at Ashen Road.

The DMU and car were to proceed through the sections under normal signalling arrangements to check the behaviour of the car on rail and to select the most appropriate route for the car under test conditions.

Because of the difficulty experienced negotiating facing point work, the original rail wheels fitted to the car were abandoned in favour of wheel sets modelled closely on those used on Permanent Way Engineer’s Rail Motors.

On Sunday 15 January 1967, a simulated test took place and all signal boxes and crossings Shelford to Chappel were opened at 05.00 for the passage of a special DMU, 05.00 ECS Cambridge to Sudbury.  Inspector Debenham travelled with the DMU and on arrival at Sudbury obtained the tablet for the Chappel/Sudbury section (Bures Signal Box having closed on 6 September 1965) and the key token for the Sudbury/Long Melford section.  The DMU then departed ECS to the Linton/Shelford section under normal signalling, Inspector Debenham retaining subsequent tablets as the train proceeded.  The car was attached to the rear of the DMU at Haverhill at approximately 06.45.  The train then continued.  On arrival in the Linton/Shelford section, Inspector Debenham was in possession of the electric tokens for the whole line.  The purpose of this was to, in effect, ‘take possession of the line’ and to allow the test to take place without the need to stop for token exchange purposes.

All tests were carried out in the Up direction (Shelford to Chappel). 

Before each test commenced the car was uncoupled from the DMU.  Inspector Debenham rode in the car with a Shell representative, each wearing a crash helmet.  Motive Power Inspector Greaves rode with the driver of the DMU.  They communicated with each other by ‘walkie-talkie’ radio.  The car itself was to be radio controlled for the filming.

It was the intention to complete four test runs on that Sunday.

Taken at Clare. Note the large white arial at the back of the car in this picture not apparent in the B&W ones. Signalman Arthur Webb is on the left of the group on the platform. Mary Cowle

On the following Sunday (22 January 1967), the test took place proper with representatives from the RAC present to ‘rubber stamp’ the proceedings.

The signal boxes and crossings opened at 05.00 for the passage of the DMU to Sudbury and return to collect the tokens.

The first test run was made at 07.30 from Shelford (using standard petrol with no additive).  The car ran out of fuel between Sudbury Station and the signal box.  The car was hauled back to Haverhill, refuelled with a gallon of Shell petrol with the ‘new mileage ingredient’ and on to Shelford.

The second test run departed Shelford at 10.30, running out of fuel just short of Bures Station.  The ‘mileage ingredient’ was a success!

Inspector Debenham remembers that they encountered a man walking a dog on the line during one of the tests near Sturmer on a snowy Sunday.  The car and the DMU sounded warnings, the man moving out of the way just in time to avoid braking.  He scrambled up the bank of the cutting horrified at seeing a car running on the railway line being pursued by a train!

Sunday 29 January 1967 was filming day.  Shelford, Linton, Haverhill and Cavendish signal boxes were opened for the passage of the special DMU, ECS 07.30 from Cambridge.  Cameramen from ‘Signal Films Ltd’ being present on the ground, on the road and airborne in a helicopter to film mock test scenes for production of a television advertisement to publicise the revolutionary new petrol.

The instructions to signalmen and crossing keepers conclude with: “It must be noted that the Railways Board are deriving a very good financial benefit for this exercise and, therefore, co-operation of all staff will be appreciated.”

At that time the line between Shelford and Sudbury was ‘hanging on by a thread’.  The Transport Users Consultative Committee had endorsed Dr Beeching’s proposal to close the line on 2 November 1965, however valid local opposition was complicating matters.  In response, British Rail Eastern Region had announced that it would require a £26,000 subsidy from local authorities in order to retain the line for one year.  The local authorities were in the process of considering this proposal.  The railwaymen of the Stour Valley must have thought that they were ‘doing their bit’ to earn some extra revenue and secure the line’s future and their jobs.

An announcement was made by British Rail on Wednesday 25 January 1967 that the initial figure of £26,000 had been increased to £52,000 because the track ‘had been found to be in poor condition and substantial repairs were necessary’.  As a result of this shock announcement the local authorities concerned withdrew from the fight to save the line, which closed to all traffic just over one month after its association with film crews, helicopters and radio control on Saturday 4 March 1967.