​Thumpers for dummies 
So you were searching the internet and have stumbled across this site. Perhaps you were looking for pictures of that rabbit from “Bambi,” or how to make fruit preserve. Sorry about that, but you are here now and you are asking yourself,“So what is a Thumper anyway?” Panic over. You're in the right place. This page will give you a brief insight into the wonderful world of Thumpers. Along the way we will look at; their history; why they were built; the different versions of thumper; their numbering and where they are preserved. 

​By the mid 1950’s the railways were contemplating the replacement of Steam locomotion that was seen to be “old fashioned,” and the Southern Railway had had a long history of using electric train stock.  However, money was tight and electrifying the whole of the Southern network was going to take time. Following political pressure to make quick improvements to some lines, a decision was made to implement Diesel trains as a short term interim measure until the whole of the network was electrified.In 1957, the first “Thumpers” appeared on the Hastings Line and were classified as “Hastings” units. 
These units were narrower than conventional trains in order to get through some of the narrow tunnels on the line. The first units produced were slightly shorter than conventional length carriages as they were originally intended to be carriages hauled behind a steam locomotive. The next batch were standard length and the last batch contained a  buffet carriage.The design of the Thumpers was radical in that, from a distance, they looked very similar to the existing 4EPB units,or 2HAL units except that the thumpers avoided the major design flaw of having to rely on an external power source. The diesel engine was mounted at floor level so that passengers could feel and appreciate the power of the engine and this diesel engine then powered electric motors that drove the train. These electric motors were very similar to those used on the electric stock and so there would be an endless supply of replacements. Genius.

​At around the same time, “Hampshire” units were also being built at Eastleigh and were very similar to the Hastings units. These Hampshire units however, were built to a standard width because there were no narrow tunnels in Hampshire. These units were designed for the non – electrified routes around the Portsmouth and Southampton area. Released in four batches, the last batch was known as “Berkshires” due to some modifications and their intended route base in the Reading area, but essentially they were the same as the Hampshire units.By 1962 these Hastings and Hampshire units were followed by the “Oxted ” units and these were intended for the non-electrified lines around East Sussex. These units contained some differences including a redesigned front with recesses for the jumper cables. Although all the variations of the units carried the same 4SRKT engine, there were some variations including differences in width, front end design, seating layout and the position of lavatories. Over time the units carried various liveries to reflect the different franchise holders and this usually resulted in different interiors as well.By the mid 1960’s, demand in rail travel had fallen and various cut backs had to be made. Certain lines such as the North Downs Line had poor passenger numbers and new stock could not be justified. Spare Hastings units and spare EMU carriages were combined to create hybrid Tadpole Units. These lasted until around 1979.

The units all carried various 4 digit identification numbers. They also were divided into sub categories, 6S, 6L and 6B (Hastings units). 3H and 2H ( Hampshire units). 3D and 2D( Oxted Units, sometimes called East Sussex sets). Later there were 3T and 3R units that were hybrids of the pre-existing sub categories, although some hybrids contained ex 4EPB stock. Then the main categories were changed with the introduction of TOPS. This meant that the simple 4 digit number was converted to a simpler 6 digit number, whereby the first three letters identified the class and the last three numbers identified the unit. Some units, having undergone some modifications, changed class and carried different numbers during their lifetime and new classes of vehicle were created to accommodate trains that were made up with carriages derived from those different classes, or other classes such as EPB electric stock. However these Hybrid units were classified out of sequence so that they bore category numbers which suggested that they were created before the Oxted units, which was not the case. Glad I was able to clear that up.

 In summary, the units carried different liveries; had different widths; different layouts; different numbers of carriages; some had buffet cars, some didn't; different fronts; different numbers; some had inter-carriage corridors, some didn't; some had official names, some didn't; some had unofficial names,some didn't and some had different guttering arrangements. Some had external lighting conduits and some did not. Some were Hampshire units, some were Hastings units, some were Oxted units and others were a mixture. Some also had a spare driving cab in the middle of the unit but most did not. Units were classified as either 6S,6L,6B,2H,3H,3D,2D,3R or 3T. Some were Berkshire units and units were later reclassified as 201,202,203,204,205,206 or 207 units but the 204 and 206 classifications were retrospectively created. Apart from that, they were all quite similar!!!!!!!.
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​As you would expect over such a long working life, some units were involved in incidents and some of these resulted in serious loss of life. A few of these are recorded on the website.Some of the units were used for private rail tours and the website has got details of some of these tours. As lines closed following the Beeching report and electrification of other lines progressed, these stalwarts of the network were moved around to cover the existing non- electrified lines. This meant that is was not unusual to find Hampshire units in Kent and Hastings units in Surrey.Over time, some units were given names whilst others became relatively famous because they were distinctively different from the rest of the fleet. One unit even had a glittering film career in “The Great St Trinians Train Robbery.”Eventually however, the units came up for replacement and there was a surplus of stock caused by branch line closures and electrification, so many were unceremoniously scrapped at the Meyer Newman scrap yard. But not every one was scrapped.

​In 2004 the remaining units were sold to a number of Heritage railways, including the Mid Hants railway; The East Kent Railway; the Lavender line; the Swindon and Cricklade; the Spa Valley railway; the East Lancashire railway; the Epping Ongar railway; the Eden Valley railway and the Dartmoor railway. Some of these preserved thumpers have been recently renovated, such as unit 1125, 1133 and 1317,1111 and others such as 1101 are still a work in progress. The website has details of the latest news on the preserved units.In 2012 I decided that a website was needed to focus interest in these units and so the Preserved Thumper website was created. Very quickly I was having trouble keeping up with work load and so Amy Adams came on board. Since that time the website has progressed beyond recognition, but we both recognise that the the biggest asset we have are those unselfish individuals who very kindly allow us to use their photos and have played a major part in the success of the site.

​There are as many different reasons to love these units as there are enthusiasts. For me they are fundamentally honest. An electric train shows no emotion, gives no indication that it may be struggling up an incline and their whining motors give very little clue if there is a problem. I remember as a child standing on Swanwick station, hearing the  Salisbury thumper express unit coming up the incline from Bursledon, then bursting through the station with a mass of vibration, noise and power, and then it was gone; leaving a deafening silence and awe struck child in its wake. When the stopping service pulled out from the station, you could feel the seats vibrate, the windows rattle and the air was filled with the rhythmic beating of the 4srkt engine. As it pulled out, the slow heart beat slowed so that for a second you thought it had stopped; then the unit moved smoothly away whilst the rhythmic thumping engine gently increased revolutions. At full speed the units were magnificent and when the power was shut off, the engine speed seemed not to correspond with the 70mph we were travelling at. These were breathing living giants that were not brought to a standstill by a few inches of snow; didn't start line fires after 2 days of warm weather and ploughed on for 50 years after their introduction. Come on, whats not to love. 

I hope that this has given you a brief insight into these amazing machines; an appreciation of the effort that goes into preserving these 55 year old units and a glimpse into this important part of our railway heritage. 

Glossary
2HAL - ( 2 carriage - Half Lavatory) An electric multiple unit with only half a toilet.
4EPB – (4 carriage - Electro Pneumatic Brakes) A version of the electrically driven moving carriages, without the benefit of a diesel engine
Beeching report – An short-sighted report that was overseen by a Minister of Transport who was (allegedly) a major stakeholder in a road building company. It is claimed that it was designed to stem losses on the network by cutting unprofitable lines and reinvesting that saved money into the existing lines. What actually happened was that lines were closed and the savings deposited into central government coffers, allegedly.
​Buffet Carriage – a carriage inserted into the middle of a Hastings unit, with no direct access to the rest of the train ( no inter-connecting corridors) and with fewer seats than a conventional carriage and fitted with the latest , hard, plastic canteen chairs. They utilised the latest technology with beautifully designed glass display cabinets that ensured your sandwiches were as warm, hard and stale as the day they were packaged. 
Electric Train Stock – A moving set of carriages that have a fundamental design flaw in that they are totally dependent on an external power source.
​EMU – Electric Multiple Unit. A moving set of carriages that have a fundamental design flaw in that they lack a diesel engine
Lavatories - A toilet facility on a thumper that required you to decide which carriage to travel in as you boarded the train, because of a lack of inter – carriage corridors, or an imaginary concept for those who used the Marsh link line and were being served by two carriage Oxted units. Just to keep Barry happy at Epping and Ongar- their unit 205205 does have an inter-carriage corridor which gives access to the Lavatories (plural). 
​Narrow Tunnels – What you are left with when your builders cut corners and build your tunnels with an inadequate depth of bricks, causing a collapse and you are left to reline and strengthen the tunnel with 2 more layers of bricks, thereby narrowing the hole for the trains.
Portsmouth – The home of world football
Southampton – Some other place up the coast near Portsmouth
Steam Locomotion – A primitive, smelly, dirty and expensive tea maker. Essentially an overgrown Victorian kettle that has multiple convictions for lineside arson. 
​Short term, Interim measure – Interpreted by the Southern Region as a potentially infinite period of time, but usually lasting a much shorter  18,250 days or 50 years.
Thumper – A nickname derived from the sound of the slow revving 4srkt diesel engine, or an annoying rabbit in a film about a talking deer that has no mummy that caused me severe mental anguish as a child. Subsequently led to the creation of “child line”.