At the end of he Second
World War it was generally accepted that the emphasis on mining had shifted from
deeply laid moored mines to ground mines laid in the shallow approaches to ports
and harbours. The large steel-built ocean minesweepers were, therefore, mostly
unsuitable for sweeping sophisticated modern mines laid in coastal and inshore
waters. As a result, a team was formed at Bath in the UK in 1947 to design the
next generation of minesweepers.
This team produced two sets
of hull drawings in 1949 for the construction of future inshore and coastal mine
countermeasures vessels, each hull design being further sub-categorized into two
variants, namely a minesweeper and a minehunter. Although no orders were
initially placed, mainly owing to a lack of funding, the impending offensive in
Korean waters led to the acquisition programme being brought forward to
September 1950. The coastal minehunter variant was, however, suspended in June
1952 and cancelled altogether in March 1953, principally because of the lack of a
suitable minehunting sonar at the time.
Although the original names
allocated to the coastal minesweepers were those of insects, this was later
changed to villages in the UK ending in 'TON'. The inshore minesweepers, in
contrast, which were to have been known as the Bird Class, received names ending
The Ton Class proved to be
a very successful design with over one hundred units built in the British yards
between 1951 and 1960. Over thirty units were subsequently transferred to
Commonwealth and foreign navies during the ensuing years, and the same basic
design was also adopted by many Western navies for their own local construction
John I. Thornycroft &
Co Ltd, of Southampton, acted as parent firm to the group of fifteen smaller
shipbuilders responsible for constructing these vessels, which were designed to
sweep both moored and ground mines. With the exception of the double mahogany
hull planking, almost the entire vessel was constructed from light aluminium
alloy and other materials with the lowest possible magnetic field to achieve
optimum safety when sweeping for magnetic mines. They were protected from
pressure mines by their low displacement, and the threat of moored mines was
greatly reduced by their shallow draught.
prevent potential damage caused by marine parasites, they were also fitted with
a protective 'Cascover' nylon sheathing on the outer shell below the waterline.
- M1101-1115 were ordered on 9
September 1950 and were to be
Red Ant, Blue Ant, Green Ant, Golden Ant, Red Aphis,
Blue Aphis, Green Aphis, Golden Aphis, Red Bee, Blue Bee, Green Bee, Golden Bee, Red
Beetle, Blue Beetle and Green Beetle.
- M1116-1117 were ordered on 20 October
1950 and were to be
Golden Beetle and
- M1118-1127, ordered on 4 April 1951,
were to be Blue Butterfly, Green
Butterfly, Golden Butterfly, Red Centipede, Blue Centipede, Green Centipede, Golden
Centipede, Red Cicala, Blue Cicala and
- M1128-1144, ordered on 28 September
1951, were to be Golden Cicala, Red
Cockchafer, Blue Cockchafer, Green Cockchafer, Golden Cockchafer, Red Cricket, Blue
Cricket, Green Cricket, Golden Cricket, Red Dragonfly, Blue Dragonfly, Green Dragonfly,
Red Firefly and Blue
Firefly & Golden Firefly.
Village names were allocated from
- M1145-1149 were ordered on 14 February
- M1150-1151, on 19 March 1952;
- M1152-1154 on 21 April 1952;
- M1155-1167 on 22 March 1952;
- and M1168-1186 on 17 June 1952.
The design called for an
aluminium-framed, wooden planked hull with non-magnetic fittings, capable of undertaking
ocean passages, and the result was a double mahogany, copper plated and very sturdy craft
which is still in service all over the world.
Early vessels had Mirrlees diesels, but from Highburton
onwards the more powerful
Napier Deltic was fitted,
and eventually the original 'Tons' were re-engined. Early members of the class had an open
bridge and the lead-ship Coniston had no top to her funnel and a short lattice mast, but
subsequent vessels had a double-finned funnel top and covered bridges were progressively
introduced. The last major external change was to revert to a tripod mast, for a new
was converted to a 'minehunter', with LL sweep gear
removed and a minehunting Type 193 sonar installed in the hull beneath the bridge. Active
rudders were fitted to allow her to position herself over the mine, and four divers and
two inflatable boats were carried to permit the mine to be blown up by hand.
(who was converted to minehunter in
1963) an auxiliary diesel-hydraulic pump-jet system was installed in 1967 to
provide quieter propulsion.
Another fourteen were modified to minehunters, some with the Sperry Towed Acoustic Generator (TAG)
others with the Multiple Towed Gradiometer (MTG).
was fitted with Sonar 193M in 1971. It was the Plessey Company's modernised
version of the old 193 and was to be the prototype for the HUNT Class 193M Mod 0
and then 193M Mod1 sonar. She was attached to the 3rd MCMS at Portland for
acceptance trials from 1972 for a couple of years before rejoining the Fleet in
the 2nd MCMS.
Six 'Tons' were transferred to the Royal Australian Navy in 1961. Also four to the Indian Navy, one to
Ghana, eight to South Africa, six to Argentina in 1968 and three to the Republic of Ireland
- Swanston, Somerleyton, Singleton,
Alcaston, Chediston and Jackton became
the Australian Gull, Hawk, Ibis, Snipe, Curlew and Teal; Curlew still being
afloat, and currently under restoration by former crew member Gary Hamer in
Tasmania, whilst Teal is now called the MV. NEAR EAST TEAL and is a
University Training Vessel in Cyprus.
- Aldington became
the Ghanaian Ejura;
- Whitton, Wennington, Durweston and Overton became
the Indian Cannanore, Cuddalore, Kakinada and Karwar;
- Thankerton, Dilston, Essington,
Hexton, Darlaston and
Lullington became the
Malaysian Brimchang, Jerai, Kinabulu, Ledang, Mahamiru and Tahan;
- Rennington, Santon, Ilmington,
Hickleton, Tarlton and Bevington became the Argentine
Chaco, Chubut, Formosa, Neuquen, Rio Negro and Tierra del Fuego.
- Alverton, Blaxton and Oulston became
the Irish Banba, Fola and Grainne.
- Dunkerton, Hazleton, Castleton,
Stratton, Packington, Oakington, Dumbelton and Chilton became the South African Pretoria, Kaapstad,
Johannesburg, Kimberley, Walvisbaai, Mosselbaai, Port Elizabeth and East London. The South African Government also commissioned two purpose-built
Ton Class vessels, the Durban and the Windhoek.
is now a Museum Ship
in Cape Town and Dunkerton
was a Diving Sports Boat, re-named MV. MADIBA after Nelson Mandela and lastly sporting her original name Golden Firefly
before she was sadly broken up recently due to old age.
is currently undergoing conversion to luxury yacht
in Dubai, after starring in the movie 'A LIFE AQUATIC' released in 2004.
Two, Edderton and Sullington, became the survey vessels Myrmidon (20 July 1964) and Mermaid,
while Invermoriston became an air-sea rescue vessel and Laleston was converted to a diving tender.
Myrmidon (Edderton) was later sold on to Malaysia, in 1969, to become Perantau ( This
means 'A Rover')
The French, Canadians and Dutch were given the drawings to copy.
Many have served as RNVR/RNR tenders, reverting to their original names when replaced by
others: Thames (Alverton, Buttington,
Woolaston), Venturer (Hodgeston, Buttington), Burnicia (Kedleston), Clyde (Amerton, Crichton),
Humber (Bronington), Mersey (Amerton, Pollington),
Solent (Warsash, ex-Crofton), Curzon (Bickington, Fittleton),
Killiecrankie (Bickington, Derriton), St David (Crichton), Kilmorey (Alfriston, Kirkliston), Warsash (Alfriston,
Boulston, Crofton), Montrose (Dalswinton, Nurton, Chediston) and Northumbria (Quainton, Hodgeston).
Late in 1971, five were converted to coastal patrol craft with 'P' numbers - Beachampton (P1007), Monkton (P1055), Wasperton (P1089), Wolverton
(P1093) and Yarnton (P1096), and a second 40mm/60 Mk 7 fitted abaft the
funnel; All five were sent to Hong Kong.
These Ton class Minesweepers were
superseded by the Peacock class, more specialised for the job, but they provided excellent
service whilst they were there.
Minehunter conversions consisted of Kirkliston, Shoulton, Bossington, Brereton,
Bronington, Derriton, Glasserton, Highburton, Hubberston, Iveston, Kellington, Sheraton,
Bildeston, Brinton, Gavinton, Kedleston, Maxton and Nurton.