Portsdown Tunnel Shelters

General Information

 Created 11-04-2002    Last update 04-12-2003

General Information

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London Road Shelter

 Wymering Shelter

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The Beginning, 1941

The Portsmouth War Emergency Committee was considering the possibility of providing the civilian air-raid shelters by tunnelling the chalk pits on Portsdown, and at a meeting held on 11 June 1941 the City Engineer reported that although he had not received definite instructions from the Ministry of Home Security to proceed, he had been told verbally to get the Contractors started on the work of excavating the tunnels. The total capacity of the shelters was to be at least 5,000 persons. 

It was agreed that admission tickets should be given on the following basis: priority to mothers with children, in which case the husbands would also be admitted. The first degree of priority in these cases to be given where the people did not have bunkered shelters of their own in which they could sleep. Claims were to be considered irrespective of income and of the areas in which people normally lived.

A report from the Assistant Chief Warden on the administration of the deep tunnel shelters was submitted on 3rd September 1941, and as a result the appointment of various personnel such as Shelter Superintendents, Shelter Wardens etc was approved. Eight Wardens, including two women, were subsequently appointed.



Joseph Parkin, the Portsmouth City Engineer, drew-up prototype plans of the shelters, initially for 1,017 people, which was rapidly expanded to 5,100 people in two separate shelters less than a mile apart: the Wymering Tunnel Shelter, and the London Road Tunnel Shelter. Note that this figure refers to the total capacity of both shelters not just to that at Wymering as is often quoted. The combined length of the shelters was 1.8 miles, and the total cost of construction was 73,298 at 1943 prices. Part of the specification stated that a person should only have to pass 60 sleeping people to get access to a clear corridor.

To speed up construction multiple adits (a horizontal tunnel leading away from the point of entry) were made into the chalk face, corresponding to every tunnel 90 degrees from it. On completion all but the main and two escape portals were sealed up. Eight adits were made for the Wymering Shelter which is why a large black painted number '5' appears in original photos next to the main entrance; it was the fifth adit from the left. The west (left) escape route being number 1, and the east number 8. Ten adits were made for the London Road shelter. Each adit was 39 feet 9 inches between centres.

The construction work was started in July 1941 by Sir Robert McAlpine's Construction Company. Unfortunately no record of this event exists with the company today.


Facilities & Features

The shelters were lined with corrugated sheeting supported by steel ribs, and the concrete floors were dished to facilitate cleansing and washing down. Bunks in three tiers were fitted after the style of the bunks in the Underground Tube stations in London. Canteen facilities were provided so that hot and cold drinks could be obtained. There was also a place where shelterers could smoke and where some form of entertainment could be given.

The first-aid post consisted of a waiting room where cases of accident or acute illness could be treated and more serious cases were passed to the sick bay. There was also an isolation section for the segregation of cases of infectious diseases, until the patients could be moved. The medical staff comprised a medical officer and two duty nurses.

It was originally intended to provide a rudimentary heating and ventilation plant at each location, consisting of a coal fired boiler house located just outside the eastern escape tunnel which would force warmed air into a shaft 6 feet by 5 feet located to the right of the main tunnel portal. However there is no evidence that this work was ever started. Ventilation was "natural" (see below), which means that there wasn't any, and all former occupants recall the stuffy atmosphere and condensation running down the walls. The shelters were not proofed against gas attack.

Two vertical shafts were provided in each shelter for ventilation and rescue. They were located at the far corners of the shelters, and consisted of a number of steel ladders each leading to their own platform (or 'interval' as they are called on the plans) within the shaft, so as to prevent a lethal fall. At ground level, above each shaft, was a "detonation cap" of 14 feet diameter by 3 feet thick concrete, the purpose of which was to stop a bomb falling clean down the shaft, and under the cap was a chamber the size of a shed with the exit to the outside offset from the main shaft for the same reason. Above ground was a square ventilation stack 6 feet 6 inches square and built of brick. Today there are no visible signs left of any of these shafts. Below is a table showing their properties:

Location Depth - feet No of platforms
London Road - west 90 5
London Road - east 80 4
Wymering - west 122 7
Wymering - east 117 7

Men and Women's toilets were provided within the tunnels, and 6 inch vertical boreholes ventilated them to the surface.  Also provided outside the shelters were the "Gentlemen's and Ladies Ablution" huts, or washrooms.

On the original plans each shelter had a water cistern storage tunnel located 30 feet above the eastern escape tunnel, which provided a water supply for the occupants. It was reached via a steel ladder from the ground. It is still un-clear whether these cisterns were ever installed.


The End, 1945

It was decided on 5 February 1945 that the Wymering Tunnel Shelter should be closed as soon as possible, and this took place at 9:00 am on the 19 February 1945. The London Road Tunnel Shelter was closed shortly afterwards. Neither shelter was used for any purpose again, despite local rumors of Cold War bunkers for the elite and special weapons repositories.  


Cold War Evaluation

Below is an account of the evaluation of the two deep tunnel shelters for possible Cold War use:

In the (Civil Defence) Region 6 of the 1949 report the "Portsdown Tunnel" (their word NOT ours) was recorded as Accommodation 5,000, cost to H.M. Exchequer was given as 73,298 at 1943 prices. The land (above) the shelter was recorded as "Land partly Corporation and partly War Department Property."

By 1952, (File Item 271) that survey had more sites listed for Civil Defence Region 6 including sites on the Isle of Wight and Oxfordshire and Berkshire for example. The Portsmouth segment reads " Portsmouth (B)", (B) = the target type, Population of 218,200 (using the 1951 Census as the benchmark), Portsdown Tunnels (note now the plural) (1) Wymering had Capacity of 2,500 on bunks, (2) London Road also 2,500 bunked, the ownership was again listed as 'jointly War Department and Local Authority". Usable as a shelter at short notice "YES", as both shelters were inside the residential area of the City the Distance from populous area was blank, (this was because the land fronting the London Road Shelter had by 1949 been authorised for use by residential caravans), the accompanying notes read " Bunking had been removed. Ventilation installation partly removed. Sanitary equipment badly damaged. Emergency lighting plant removed" it was "Estimated 6,000 needed to reinstate."

Letters to and from the City Council indicated that further internal surveys were carried out every third year -on the average- from 1954 until 1963. The results of these inspections were not recorded in this dossier. Therefore they remain to be found in other files either in the City Records, or at the National Archives.

Peter Cobb & Keith Ward November 2003


Extracts from the War Emergency Notes

Below are some extracts from the Portsmouth City Council War Emergency Committee papers, which relate to the deep tunnel shelters.
December 1941
...the  London Road Deep Shelter had sufficient users to warrant the use of a former 'large Piggery Hut (ex Warren Farm. Petersfield)" as a Nursery. There were problems using the chalk tunnels as shelters with ,: - Damp and cold conditions, even so. the Regional Commissioner annexed of a certain tunnel [which one not defined on original] to store mattresses and palliasses of the Regional Reserve which in its turn required the provision of a "Drying Room Hut" outside (the Tunnel mouth) to air and dry the bedding on a weekly rotation
    At l000Hrs of 29 December 1941 the "Full City Council" inspected in great detail the Wymering Tunnels. As a result thereof the City Council insisted that a heating plant was installed able to heat the Tunnels to a minimum of 50Fand that special Childrens' Toilets be erected with not less than "12 Chambers be issued" and that the Tunnels be disinfected on a weekly basis and the internal signs be improved forthwith.
At the London Road  Deep Tunnel Shelter the City gave permission for the Ministry of Health to house their "Southern Regional Portable X RAY Unit Trailer " under the overhang of the Cliff on the newly formed hardstanding. This X RAY Unit was one of several equipped to act as an emergency replacement to, or for, similar fixed X Ray machines that may have been put out of action by the effects of enemy bombing. etc. [The installation of this equipment further fuelled the myth that an underground hospital existed under Portsdown].
January 1942

Both sets of the Portsdown Hill deep shelters had finished fully fitting out "Medical Aid Posts"

New bus service was inaugurated to serve both of the new tunnel shelters.

16 February 1942

Main tunnel "F" at the London Road deep tunnel shelter was opened to the public. 

In the Wymering deep tunnels modifications continued with the installation of seating in cross tunnel "BU-HU" and the provision of lavatories therein. 

May 1942

Wymering shelters: Trekking problems and the local population using them only on a "casual alert" basis rather than as regular nightly stays. Tickets for persons living or working on Portsea Island were obtained from No 9 Hampshire Terrace. 

    At both sets of shelters the possibility of failure of the water supply to the lavatories in the event of very heavy bombing was considered. Portsmouth Water Company to arrange a gravity fed supply to the London Road shelter from the George [Inn] reservoir.

June 1942

Portsmouth Water company ready to install 2 x 1,200 gallon emergency water tanks at the entrances of both shelters. 

    Shelter Modifications: installing wire mesh doors to the Canteen, Toilet blocks and bedding store to try and improve circulation of the air. In the London Road shelter solid fuel cooking apparatus was noted. One of the Tunnel Shelters was required by the Government to be used a an "Emergency Hospital" with 300 beds.

London Road deep shelter: a pram shed and Nursery was established.

July 1942
Invasion medical matters: To up-grade the Emergency Hospital in the tunnel shelters and improve security, internal gates were fitted to the inner entrances of the wards.
October 1942
At London Road deep shelter a drying room had to be added to the Nursery block as some children and infants were arriving very wet on rainy days due to the distance from both Cosham Railway Station and the lack of buses. 
December 1942
London Road deep shelter: Accident. As persons unknown has forced off the wire mesh to the ventilation shafts, a boy had fallen down one and had to be taken to hospital.
January 1943
The Cosham Mobile First Aid Unit is to re-locate to a part of the London Road Tunnel Shelter.
April 1943
Tunnel shelters: Improvements to ventilation, Haden & Sons (Bournemouth) to supply and fix at cost of 695.
June 1943
Problems with crowding the entrance to the Wymering Tunnel Shelter during alerts.
18 October 1943

Inquiry into sudden death of child in Wymering Tunnel Shelter. Death of child was "accident" due due to the child not having been treated for internal wounds soon after bombing and entering the Tunnel when in a dangerous condition therefrom.

Wymering tunnel set up an infectious diseases ward.

30 January 1944
Tunnel Shelters: Due to damp conditions a programme of de-rusting and then painting of the bunks cost 200.
April 1944
Tunnel Shelters reported overcrowding due to becoming so popular, so Police to control entry numbers.
May 1944

A few difficulties were reported of the use by heavily pregnant women of the Portsdown Tunnel Shelters as the "Emergency Hospital" in the shelters had very few maternity facilities.

Early in the war (1939-40), the City Engineer had acquired 20 portable electric generating sets, 2 of these had been sent to the tunnel shelters - 1 to each shelter. These were to be used to power the forced ventilation plant on the sewage system in the event of Enemy Action cutting of the electrical supply to the tunnels.

Gates were installed at both sets to tunnel shelters.

Loudspeakers and "Tannoy" type Public Address System installed in tunnels. This comprised: 12 x M30 amplifiers; 2 x microphones, 42 loudspeakers, and was supplied by Grapions Ltd at a cost of 46-11.

The death due to natural causes of Mrs E.F. Bailey was noted in the London Road Tunnel Shelter.

June 1944

Wymering Shelter approach path now have a tarmac surface due to earlier falls on 2 and 4 June resulting from persons tripping over loose rocks in the dark.

The Government have replaced the petrol driven Portable Electrical Power sets (see May 1944 above) with diesel generating sets free of charge

July 1944
Deep Tunnel Shelters: disinfection programme activated again following on from the Flying Bomb attacks on certain areas of the city. The number of infections and contaminated clothing brought into the tunnels has risen. Extra "Millbank Mobile Disinfector" supplied.

With thanks to:

Danny (Calgary Canada), Paul Wells, Barry Jenson, 

Adrian McGachie and Peter Cobb UKFC.

Also staff at

Portsmouth City Council Engineers and Portsmouth City Records Office.

There are three sections for this topic. You can select which one you view by clicking a link in the box below

General Information

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London Road Shelter

 Wymering Shelter