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Created Sep 2012, last edited:
04/10/26, 00:10
Introduction
Three-quarters of a mile south of Sutton Gault there is a curious feature of the Washes. The norh-west barrier bank of the Old Bedford River has a large loop
or kink in it known as "The Gullet".
map: OS; satellite view: Google; right: Peter Cox Aug 2013, Olympus E-620
Here, three vertical concrete slabs stand in line running parallel to the Old Bedford River, just out of sight to the right. The slabs can be clearly seen on the Google satellite image and this photo.
In dry conditions it is a peaceful, grassy area where horses often graze; in wet weather it can become damp or swampy in the centre; and when the Ouse Washes are flooded this area can be too. In extreme flood conditions so deep the concrete slabs are allmost submerged.
(The small river going around the west of the loop is the Counterdrain.)
The casual observer may wonder what the slabs are, or were, as I did, and why the bank goes round them.
In fact the loop and the slabs are unrelated, apart from location.
The loop pre-dates the slabs by more than three centuries and was a bank repair following a breach. The bank engineers of the mid-17th C found the land under the breach was porous, and built a new bank on firmer land to skirt around the porous area.
Darby1 attributes the name to old dialect for a breach - "gull"- and says that there is reference to a Gull "neer Tubbes his howse" in the Bedford Level Corporation's accounts for 1655. Today there is a Tubbs Farm half a mile west of the Gullet (see map).
The slabs go back to 1969 and are concrete piers that once supported an elevated concrete "guideway" track planned to run between Earith and Sutton Gault on which a scientific marvel of the time, a magnetically powered and air levitated "Hovertrain" would be tested at high speeds.
Luckily for inquisitive walkers, Cambridgeshire County Council erected an information board at the Gullet a few years ago which has some interesting, although not entirely accurate, information about the Hovertrain experiments, but strangely not about The Gullet itself.
The site of the board is also strange, being at ankle level to those on the footpath, and on a steep slope making closer inspection difficult, as my friend and fellow local
historian Chris Holley demonstrates below. It is also furthest away and facing away from Sutton Gault from where most walkers approach.
3 photos above: Peter Cox (aka Eddy) Aug 2013, Olympus E-620
I'm Peter Cox, although when I started my researches and this page in 2012 I did so under an online alias as many do.
Scroll down to follow the story of the Hovertrain Experiment or choose a section to jump to from the drop-down menu.
I came across the Gullet by chance in 2012 whilst using Google Earth on my PC following the line of the Old Bedford River, during researches into the Ouse Washes. I was curious about the kink in the river, but much more so about the concrete piers and "the Hovertrain Experiments".
I couldn't remember anything about that nor had friends or neighbours and wondered why a piece of Britain's recent history had apparently become forgotten.
I soon discovered it certainly hadn't been, in fact the Hovertrain itself, correctrly known as RTV31, had been preserved first at Cranfield for 21 years then at Railworld in Peterborough since 1995, where many people had seen it. There were helpful information boards at Railworld showing the time line of the development of the idea, and some basic facts about the trials, and a 6ft long wooden model and other artifacts in a portacabin-style modular unit.
However, the story of the experiments was not (then!) widely known so I set out to try to fill some of the gaps. Many people added pieces to the story. Some worked on the project or had relatives or friends who had; some lived nearby; I was also helped by several museum trustees, by on-line videos of old TV films, and by my friend Mike Petty, the Cambridgeshire historian, who supplied contemporary newspaper cuttings and photos which really helped.
But a big breakthrough was when a French expert on tracked hovercaft worldwide, Jerôme Tillier, contacted me in 2015. He provided details of his own findings, and most importantly told me that a very extensive official archive of the experiments existed near Gosport. However, getting access to them proved difficult.
The Archives
I refer below to the "bonanza" of finding answers to most of the questions no one had been able to help with.
I have recorded that very important find in detail below as it probably hasn't been done so elsewhere.
2015
I discovered from Jerôme Tillier, a French authority on tracked hovercraft worldwide, that a huge amount of
original douments
of Tracked Hovercraft Ltd
("THL") the company who undertook the Hovertrain project, was in store near Gosport and largely untouched since being acquired. (I later discovered that they had been there prior to 2008, but
probably a lot longer, possibly as far back as 1997.
2016
I suggested to Cambridge Archeological Unit who had been commissioned (indirectly with Heritage Lottery funds) to record the Hovertrain project, that they should try to acquire
the collection, but no contact was made.
2017
I was appointed Hon. Hovertrain Archivist to sort out their collection which had become somewhat dislocated and jumbled.
My office was in Room 4 of the Globe House
2018
In March I enrolled as a Railworld Working Volunteer (#1126)
and, Bonanza! With the help of Railworld's Chair of Trustees, Brian Pearce (now 'MBE') I was enabled to "rescue" the archives at Gosport (which were on the verge of being destroyed!)
making two trips in my estate car to do so. The most imported items were deposited at Railworld: the 5 volumes of THL's bound minute books, 35mm film in cartons
and canisters, an A2 size bound book of the civil engineering plans, and 2 huge albums of media reports. Lack of space at Railworld has meant that the vast majority of
the THL archives has been stored off-site, with me as hon.
curator. Most files appear to have been bundled-up in an orderly
manner at Earith in spring 1973 after the Govt closed the
project but some unmarked stuff mostly relating to the winding
up looks like a quick desk-clearing in London in 1978. I listed
the vast majority on spreadsheets, and digitised a number of
documents, particularly those relating to the accidents which
contributed to the project's demise.
2019
At Railworld, I completed
digitising and catalouging their collection; and I erected
shelving on two walls of room 4 for more THL archives, but the
arrival of Covid restricted activities then in 2020 domestic
duties (caring for my wife 24/7) brought it to a standstill.
Below and on other pages I have described the Hovertrain project and summarised some of the events and features of the experiments,
but please note this subject is huge, and this is just a scratch on the surface. In particular, I have not attempted to cover
the technology involved in anything other than a simplistic way.
The Project
The aim of the Hovertrain developers, Tracked Hovercraft Ltd, (THL), a subsidiary of the government agency the National Research
Development Corporation (NRDC), was to provide very
high speed (240-300 mph)
inter-city travel on dedicated guideways, with trains (or just a single carriage) transferring or connecting somehow
to conventional rail lines or existing stations. Examples of envisaged journey times from London were 20
minutes to Birmingham, and under 90 minutes to Edinburgh. image above right: coloured artists impression from ex-THL engr, Cliff Gardner
Safety was a major selling point. No head-on collisions possible due to trains going backwords and forwards on their own track (known as bi-directional working) and there wouldn't be any derailments either because the trains straddled the track - they coudn't fall off! Official HDL/THL image with coloured addtions by Peter Cox from his slide-show talk Aug 2018
The experiments by THL built on work by organisations elsewhere during the 1960s, combining the principle of frictionless suspension on a cushion of air (as
already used on 'hovercraft') with motive power using electromagnetism. THL themselves experimented with a scale model over a 300 feet long track near their Cambridge HQ while the facilities at Earith were under construction.
The project ended after only three years due to lack of further government funding. Some say it was lack of vision by politicians, others that it was a pragmatic decision as the idea was impracticable in the UK due to the established rail infrastructure and crowded urban areas which would be better served by British Rail's planned "tilting" Advanced Passenger Train (which later was also abandoned).
railway horses
Horses hauled the very first trains and still played a part even after steam, diesel and
electric power were introduced. The last BR horse was retired from shunting duties at Newmarket in 1967, the
year this project was founded.
Brief Chronology
year
note
1967
Tracked Hovercraft Ltd (THL) formed as subsidiary of
National Research Development Corporation (NRDC), a govt agency, to take over the project from another NRDC
company, Hovercraft Delelopment Ltd, which did initial tests in Hythe, nr Southampton.. £5¼m earmarked for Hovertrain test project. 200 miles of disused railway were said to have been considered as a test site, but the side of the Old Bedford River
was chosen [possibly because it was near to the academic centre of Cambridge?]
1967
"Application to Great Ouse River Authority
[GORA] specified a
20 mile long track between Earith and Welney." [??]
9
1967 July
GORA approved in principle the NRDC application to
lease a 20-mile strip of land for 21 years. Test bores showed subsoil
can stand the weight of the hovertrack
18
1967 July
Prof. Laithwaite, inventor of the Linear Induction
Motor, resigned from BR after 6 yrs as a consultant, and joined
THL.
18
1968
Earith
chosen as the site for a 6,300 sq.ft engineering centre and
"hangar" and the start of the
line running parallel with the Old Bedford River.
12
1968 Mar
Admin and R&D offices set up in Ditton Walk, Cambridge
12
1969 June
Construction started at Earith
21
1970
Model vehicle tested on a 300 ft
track at Fen Ditton
17
1970 June
Construction of one mile of
guideway track completed at Earith
21
1970 July
a beam failure occured on
high-level track. 2 beams & 2 columns lost. "Track laying
terminated"
21
1970 Aug
A concrete beam "collapsed" [at
Sutton Gault]
during construction, but eventually sufficient track completed for early trials.
4
1970 July
"collapse of some of the track"
according to Dr. Bard in evidence to Select
Committee 1973
20
1970 July
"a constructional failure" according to Tom Fellows,
MD of THL, writing in 1973
20
1971 Jan
foundation faults discovered just ahead of where
track being re-erected. (Tom Felows)
20
1971 Aug
RTV31 delivered to Earith from
Vickers-Armstrong in Swindon
1971 Dec
First public demonstration of train RTV 31 achieved
12 mph !
4
1972 Feb
Imperial College devised a new form of LIM giving
magnetic levitation as well as guidance and propulsion. which worked
well on a model, but power too low for full scale use
1972 June
More powerful motor fitted during 3-week overhaul "Work going on to finish a 2 mile extension". Engineers now said to want a 12 mile track in order to attain 300 mph
I said at the start that the three concrete slabs (piers) were all that was now visible of the track, but another feature of the project, the heart of the Earith site - the workshops and 'hangar' where the test vehicle was assembled and kept - still exists - although hidden away as shown further down this page.
Above right is the rear of
the hangar in 1970 with its door closed. To the right of the hangar is a small peaked-roof shed and behind that is the odd roofline of another
building. Much more about that below.
On left the train is on the concreted working area north of the
hangar in 1971, having been towed out by an ex-forces Austin Champ 4x4.
Out of sight to the right is the gantry hoist. The doorway is indicated by the lights inside. Photos above cropped from press clippings courtesy of Mike Petty
On the south-east side of the hangar was a two storey office and admin
block with huge radio masts fitted on the roof.
The masts transmitted a narrow-beam UHV radio signal
which enabled remote control of the train from the
control room below.
The radio link also enabled data to be sent
from the train, and that was recorded on magnetic tape and
later fed into an off-site "main-frame" computer at the
Atlas Laboratory at Harwell, Berkshire.
The control room on the upper floor of the office block had a
huge window facing north-east giving a good view of the
outdoor working area the whole
length of the test track.
It also had a very impressive array of switches, buttons and knobs.
all 3 above from archives of AP Television, Dec 1971
The "big window" was approximately where the fire door is at far left of photo.
Note the row of small metal-framed "Crittal" windows in the brick wall here and
above. The whole building has been extended north-east (towards the camera) from the traffic cone.
(See below) Photo: Peter Cox, 2013, Olympus E-620
The hangar has been occupied since c1995 by KLM Engineering who also
occupy the buildings now connected to the north-east end, plus the
parking land beyond. The whole site is private, and anyone wishing to
view must obtain prior permission.
The north-east extension hides the original
back wall, most of which has in any case been cut away, leaving only
the upper part, seen here from within.
The top of the old doorway still exists, mostly hidden in this photo by the large white pipe. Photo: Peter Cox, 2013, Olympus E-620
The north-west side (left) has been extended and the roof, which
was black in 1971 but now white, covers the new side extension and
also the offices on the south-east (right) side which have also been
extended.
The original width of the building is indicated by the area of larger
roof-lights.
Newer buildings now connected to the n-e extension of the hangar building are where the
outdoor working area and gantry hoist were situated. KLM also have the land beyond which is where the track
left the works area and curved to the side of the Old Beford barrier bank. aerial photo: cropped from KLM website image.
Slide show talks
In Dec 2015 I began giving slideshow talks and made many over much of East Anglia until Covid put a stop in April 2020. I restarted in 2022 but in April 2026 gave my last one outside my home parish due to increasing travel problems, poor roads and cost of derv.
Postscript
Sadly, by 2025, RTV31 had deteriorated having been stored outside for nearly 50 years without roof covers for a long time and the metal framework within the body shell had corroded and weakened.
A further problem was that the supporting beam has signs of stress at the ends. Both train and beam were deemed unsafe, and public were unable to view close up.
But the Railworld volunteers have NOT given up. They have constructed a new welded metal supporting frame in-house to replace the concrete beam
The Hovertrain has been stripped of its outer body, the "chassis" cut into two to enable a crane to lift the parts safely from the beam to the frame.
There is much to add and no doubt some corrections to make, but this page will never be any more than just a brief outline of the project.
The Gullet and the Hovertrain Experiments
Created Sep 2012, last edited: 04/10/26, 00:10
Introduction
Here, three vertical concrete slabs stand in line running parallel to the Old Bedford River, just out of sight to the right. The slabs can be clearly seen on the Google satellite image and this photo.
In dry conditions it is a peaceful, grassy area where horses often graze; in wet weather it can become damp or swampy in the centre; and when the Ouse Washes are flooded this area can be too. In extreme flood conditions so deep the concrete slabs are allmost submerged. (The small river going around the west of the loop is the Counterdrain.)
The casual observer may wonder what the slabs are, or were, as I did, and why the bank goes round them.
In fact the loop and the slabs are unrelated, apart from location.
The loop pre-dates the slabs by more than three centuries and was a bank repair following a breach. The bank engineers of the mid-17th C found the land under the breach was porous, and built a new bank on firmer land to skirt around the porous area.
Darby1 attributes the name to old dialect for a breach - "gull"- and says that there is reference to a Gull "neer Tubbes his howse" in the Bedford Level Corporation's accounts for 1655. Today there is a Tubbs Farm half a mile west of the Gullet (see map).
The slabs go back to 1969 and are concrete piers that once supported an elevated concrete "guideway" track planned to run between Earith and Sutton Gault on which a scientific marvel of the time, a magnetically powered and air levitated "Hovertrain" would be tested at high speeds.
Luckily for inquisitive walkers, Cambridgeshire County Council erected an information board at the Gullet a few years ago which has some interesting, although not entirely accurate, information about the Hovertrain experiments, but strangely not about The Gullet itself.
The site of the board is also strange, being at ankle level to those on the footpath, and on a steep slope making closer inspection difficult, as my friend and fellow local historian Chris Holley demonstrates below. It is also furthest away and facing away from Sutton Gault from where most walkers approach.
I'm Peter Cox, although when I started my researches and this page in 2012 I did so under an online alias as many do.
Scroll down to follow the story of the Hovertrain Experiment or choose a section to jump to from the drop-down menu.
I couldn't remember anything about that nor had friends or neighbours and wondered why a piece of Britain's recent history had apparently become forgotten.
I soon discovered it certainly hadn't been, in fact the Hovertrain itself, correctrly known as RTV31, had been preserved first at Cranfield for 21 years then at Railworld in Peterborough since 1995, where many people had seen it. There were helpful information boards at Railworld showing the time line of the development of the idea, and some basic facts about the trials, and a 6ft long wooden model and other artifacts in a portacabin-style modular unit.
However, the story of the experiments was not (then!) widely known so I set out to try to fill some of the gaps. Many people added pieces to the story. Some worked on the project or had relatives or friends who had; some lived nearby; I was also helped by several museum trustees, by on-line videos of old TV films, and by my friend Mike Petty, the Cambridgeshire historian, who supplied contemporary newspaper cuttings and photos which really helped.
But a big breakthrough was when a French expert on tracked hovercaft worldwide, Jerôme Tillier, contacted me in 2015. He provided details of his own findings, and most importantly told me that a very extensive official archive of the experiments existed near Gosport. However, getting access to them proved difficult.
The Archives
I refer below to the "bonanza" of finding answers to most of the questions no one had been able to help with. I have recorded that very important find in detail below as it probably hasn't been done so elsewhere.My office was in Room 4 of the Globe House
and, Bonanza! With the help of Railworld's Chair of Trustees, Brian Pearce (now 'MBE') I was enabled to "rescue" the archives at Gosport (which were on the verge of being destroyed!) making two trips in my estate car to do so. The most imported items were deposited at Railworld: the 5 volumes of THL's bound minute books, 35mm film in cartons and canisters, an A2 size bound book of the civil engineering plans, and 2 huge albums of media reports.
Lack of space at Railworld has meant that the vast majority of the THL archives has been stored off-site, with me as hon. curator. Most files appear to have been bundled-up in an orderly manner at Earith in spring 1973 after the Govt closed the project but some unmarked stuff mostly relating to the winding up looks like a quick desk-clearing in London in 1978. I listed the vast majority on spreadsheets, and digitised a number of documents, particularly those relating to the accidents which contributed to the project's demise.
Below and on other pages I have described the Hovertrain project and summarised some of the events and features of the experiments, but please note this subject is huge, and this is just a scratch on the surface. In particular, I have not attempted to cover the technology involved in anything other than a simplistic way.
The Project
The aim of the Hovertrain developers, Tracked Hovercraft Ltd, (THL), a subsidiary of the government agency the National Research Development Corporation (NRDC), was to provide veryimage above right: coloured artists impression from ex-THL engr, Cliff Gardner
Official HDL/THL image with coloured addtions by Peter Cox from his slide-show talk Aug 2018
The experiments by THL built on work by organisations elsewhere during the 1960s, combining the principle of frictionless suspension on a cushion of air (as already used on 'hovercraft') with motive power using electromagnetism. THL themselves experimented with a scale model over a 300 feet long track near their Cambridge HQ while the facilities at Earith were under construction.
The project ended after only three years due to lack of further government funding. Some say it was lack of vision by politicians, others that it was a pragmatic decision as the idea was impracticable in the UK due to the established rail infrastructure and crowded urban areas which would be better served by British Rail's planned "tilting" Advanced Passenger Train (which later was also abandoned).
The last BR horse was retired from shunting duties at Newmarket in 1967, the year this project was founded.
Brief Chronology
£5¼m earmarked for Hovertrain test project.
200 miles of disused railway were said to have been considered as a test site, but the side of the Old Bedford River was chosen [possibly because it was near to the academic centre of Cambridge?]
"Work going on to finish a 2 mile extension".
Engineers now said to want a 12 mile track in order to attain 300 mph
The Hangar
I said at the start that the three concrete slabs (piers) were all that was now visible of the track, but another feature of the project, the heart of the Earith site - the workshops and 'hangar' where the test vehicle was assembled and kept - still exists - although hidden away as shown further down this page.On left the train is on the concreted working area north of the hangar in 1971, having been towed out by an ex-forces Austin Champ 4x4. Out of sight to the right is the gantry hoist. The doorway is indicated by the lights inside.
Photos above cropped from press clippings courtesy of Mike Petty
The masts transmitted a narrow-beam UHV radio signal which enabled remote control of the train from the control room below.
The radio link also enabled data to be sent from the train, and that was recorded on magnetic tape and later fed into an off-site "main-frame" computer at the Atlas Laboratory at Harwell, Berkshire.
It also had a very impressive array of switches, buttons and knobs.
all 3 above from archives of AP Television, Dec 1971
The whole building has been extended north-east (towards the camera) from the traffic cone. (See below)
Photo: Peter Cox, 2013, Olympus E-620
The hangar has been occupied since c1995 by KLM Engineering who also occupy the buildings now connected to the north-east end, plus the parking land beyond. The whole site is private, and anyone wishing to view must obtain prior permission.
The top of the old doorway still exists, mostly hidden in this photo by the large white pipe.
Photo: Peter Cox, 2013, Olympus E-620
Newer buildings now connected to the n-e extension of the hangar building are where the outdoor working area and gantry hoist were situated. KLM also have the land beyond which is where the track left the works area and curved to the side of the Old Beford barrier bank.
Postscript
Sadly, by 2025, RTV31 had deteriorated having been stored outside for nearly 50 years without roof covers for a long time and the metal framework within the body shell had corroded and weakened.
A further problem was that the supporting beam has signs of stress at the ends. Both train and beam were deemed unsafe, and public were unable to view close up.
But the Railworld volunteers have NOT given up. They have constructed a new welded metal supporting frame in-house to replace the concrete beam
The Hovertrain has been stripped of its outer body, the "chassis" cut into two to enable a crane to lift the parts safely from the beam to the frame.
There is much to add and no doubt some corrections to make, but this page will never be any more than just a brief outline of the project.
Some photos are the copyright of the photographers but licensed for reuse here under this Creative Commons Licence
If you think there are any errors or ommissions on this page or would like to comment, please e-mail me and your response will be added.