top of page

Deep Sea Technology at
Siebe Gorman:
From World Wars to world records

The industrial estate’s ties to national defence date back to the interwar period; as the Second World War loomed, the site was home to the Parnall Aircraft Company who developed state-of-the-art machine gun turrets for RAF bombers.

Around the same mid-1930s period, Siebe, Gorman and Co. moved some of its operations to Chessington from Lambeth. World leaders in diving apparatus, respirators and gas masks, Siebe Gorman wanted a location away from homes and businesses to conduct some of its more top secret and dangerous experiments. But when its Lambeth site – known as Neptune Works – was flattened during the Blitz in May 1941, everything that could be rescued was moved to Cox Lane, the site becoming known as Neptune Works II.

Situated on Davis Road, Neptune Works II featured several deep-water tanks that were used to simulate deep sea diving conditions. There were also pressurised barometric chambers, which were used to simulate high altitudes and test new aircraft breathing masks being secretly developed for the Air Ministry. 


After World War II operations at the site scaled down significantly. But Siebe Gorman would still have a role to play in projecting Britain’s influence on the world stage in 1954, when Donald Campbell identified their deep-water tanks as a suitable testing ground for his Bluebird K7 hydroplane. Born in Kingston upon Thames to Sir Malcom Campbell, Donald wished to reclaim the world water speed record for his country and the Campbell family, following the loss of Sir Michael’s record to American Stanley Sayres in 1950.

Donald designed and built a new all-metal jet-propelled hydroplane, with the Bluebird K7 capable of travelling at up to 300 mph. A year ahead of his first water speed world record attempt, Donald enlisted a team of Siebe Gorman engineers at Chessington and used the company’s tanks to test its emergency escape procedure.

A superstar of the day, news of Donald Campbell at Siebe Gorman drew the world’s press and TV crews to Chessington to witness the spectacle, both from above the waterline and below the surface; the special tanks had large glass windows so people could watch without getting wet. On 23 July 1955 the Bluebird K7 clocked up more than 202 mph on Ullswater lake in Cumbria, bringing the record back to Britain.


Donald would later go on to set seven new water speed records in the K7 – and in 1964 became the first person to set the water and land speed records in the same calendar year, a feat that remains unmatched today.

Donald Campbell sadly lost his life in 1967 when pushing for his eighth record on Coniston Water; his body was propelled 40m to the lakebed and could not be found for over 30 years. When it was eventually discovered in September 2001, it was in large part thanks to deep-water technology pioneered by teams in Chessington.

Prior to their involvement in the Campbell story, Siebe Gorman tanks were host to the first ever live underwater television broadcast. Siebe Gorman had teamed up with Marconi to develop the underwater camera system, with each camera weighing 900kg and capable of transmitting pictures from 455m beneath the surface – at a cost of £3500 per camera. On 26 August 1952 the cameras broadcast images of model divers working on the stern of a sunken ship, with the pictures shown at the 19th National Radio and Television Exhibition in London. This record remains acknowledged by the Guinness World Records today.

Although Siebe Gorman was eventually bought out and ceased operations on Cox Lane by the 1980s, they and other engineering firms left a legacy in Chessington that endures today. The site had quadrupled in size by the 1960s, with many of the industrial units filling up with specialist engineering firms manufacturing niche components. This includes Andre Rubber, which made injection moulded rubber seals for diving specialists, and Mollart, who specialise in deep hole drilling and continue to operate on the site today.

The industrial estate also appealed to defence contractors throughout the Cold War period, with Decca (Radar Division) onsite throughout the 1950s and 60s, later splitting into Siemens Plessey and Decca RACAL. Their work focused on signals processing and developing voice encrypted radios for the British military, police and other government officials. In 2000, the company was acquired by defence firm Thales. This company remained on-site until 2010 when its brick unit was demolished and the site sold.

The Donald Campbell Story
- David Tremayne


David Tremayne is a motorsports journalist who has a particular interest in the land and water speed records. In 2005 Tremayne's biography of Donald Campbell, ‘Donald Campbell: The Man Behind the Mask’, was released. He spoke to The Community Brain about Campbell's upbringing, character and record breaking attempts.

Donald’s domineering father
00:00 / 01:14
Developing the K7 and the Siebe Gorman test
00:00 / 01:20
Becoming an inspiration
00:00 / 01:40

Working for Siebe Gorman 
- Dawn Moore

In July 1960, a 15 year old Dawn Moore started her first job as a junior clerk at Siebe Gorman where she stayed for a year. She recalled the diving tanks, social activities, and a unique Siebe Gorman employee perk: company sponsored diving lessons.

364176459_1820064811763203_3053726876902801797_n 2.jpg
The job and the tank Dawn Moore
00:00 / 01:04
Complementary diving lessonsDawn Moore
00:00 / 01:20
Social club Dawn Moore
00:00 / 00:33

Dawn (front row, haunched 3rd from left) and her Siebe Gorman colleagues take a break from playing football, circa 1960/61.

Discover more about Cox Lane Industrial Estate

bottom of page