The Hastings Line was built by the South Eastern Railway between 1845 and 1852 across the difficult terrain of the High Weald.

The solution was to add additional rings of bricks inside the tunnels affected.

[5] From 1931, the Southern Railway[c] Schools class steam locomotives were introduced to work the Hastings Line.

[8] The carriages built for the Hastings Line were refurbished at a cost of £100,000 in the early 1950s with the intent of giving them a further ten years' service.

These vehicles were to be built to the same length as existing stock in use on the Hastings Line, 56 feet 11 inches (17.35 m).

[7] Further objections were on the grounds of cost and that the necessary works would disrupt traffic on the line for a year.

[12] Taylor Woodrow built a new depot at St Leonards-on-Sea, East Sussex, where the Hastings Units were to be serviced and maintained.

[13] All units were powered by two English Electric 4SRKT Mark II diesel engines.

[22] ‡ 60507-8/20/706 were in unit 1007 at the time of the Hither Green rail crash, and were withdrawn in November 1967 as a result of damage sustained.

[17] Formation was similar to the 6S and 6L units, except that an unclassified buffet car replaced one of the second class carriages.

[24] Original 6B Units †60036 withdrawn March 1980 due to damage sustained in a derailment at Appledore.

[27] The 6S units were delivered in January 1957, outshopped in the standard green livery, including the ends of the motor coaches.

On 25 February, unit 1003 made a demonstration trip from Waterloo to Bournemouth West, where it was declared a failure due to an overheated bearing on one of the traction motors.

[30] From 1962, small yellow warning panels were painted on the ends of the motor coaches.

They were replaced by TSOs from unit 1007, which was reduced to four cars and used on Ashford – Hastings services.

[32] This was to allow steam locomotives to be withdrawn from the Tonbridge – Redhill – Reading route.

Due to the difference in body widths between the Hastings Line and EPB stock the quickly gained the nickname "Tadpoles".

[34] From mid-1966, the Hastings Units were repainted in an all-over blue livery as they went through the works for repairs.

A few units, such as 1037, gained full yellow ends whilst still in green livery.

It regained the sixth in October following the disbandment of two more 3Rs and their replacement on the Tonbridge – Reading service by Class 119 diesel multiple units.

The buffet car on the 18:45 Charing Cross – Hastings train was specially manned.

[37] On 28 October 1983, it was announced that the line was to be electrified and the Hastings Units would thus be withdrawn from service.

[22] The Hastings Units were showing their age, and apart from the first ten sets built, had blue asbestos, which British Rail was committed to eliminating from its trains by the end of 1987.

[40] Buffet car 60755, which had been withdrawn from 6B 1031, was rebuilt to an inspection saloon at Stewarts Lane in 1969–70.

Numbered DB975025 (later TDB975025), it is notable for conveying the Prince and Princess of Wales from Waterloo to Romsey following their wedding on 29 July 1981.

It also conveyed Pope John Paul II from Gatwick Airport to London Victoria station on 28 May 1982.

Numbered RDB975386, "Laboratory 4" and subsequently named Hastings, it was used to develop the tilting suspension system used on the Advanced Passenger Train (APT).

The vehicle was subsequently converted back to conventional suspension and saw use in tests that led to the introduction of the Class 91 locomotives.

[65] Trailer first 60708 was built in 1957 as part of unit 1012. purchased i 1990 by Hastings Diesels Ltd, it has not been restored.

It was at the Electric Railway Museum, Coventry by September 2011, where it is being restored in original research division livery as Laboratory 4.