The Ham class was a
class
Class or The Class may refer to:
Common uses not otherwise categorized
* Class (biology), a taxonomic rank
* Class (knowledge representation), a collection of individuals or objects
* Class (philosophy), an analytical concept used differently ...
of inshore
minesweeper
A minesweeper is a small warship designed to remove or detonate naval mines. Using various mechanisms intended to counter the threat posed by naval mines, minesweepers keep waterways clear for safe shipping.
History
The earliest known usage of ...
s (IMS), known as the Type 1, of the British
Royal Navy
The Royal Navy (RN) is the United Kingdom's naval warfare force. Although warships were used by English and Scottish kings from the early medieval period, the first major maritime engagements were fought in the Hundred Years' War against Fr ...
. The class was designed to operate in the shallow water of
river
A river is a natural flowing watercourse, usually freshwater, flowing towards an ocean, sea, lake or another river. In some cases, a river flows into the ground and becomes dry at the end of its course without reaching another body of ...
s and
estuaries
An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environme ...
. All of the ships in the class are named for British place names that end with
-"ham". The parent firm that was responsible for supervising construction was
Samuel White of
Cowes
Cowes () is an English seaport town and civil parish on the Isle of Wight. Cowes is located on the west bank of the estuary of the River Medina, facing the smaller town of East Cowes on the east bank. The two towns are linked by the Cowes Fl ...
, Isle of Wight.
Unlike traditional minesweepers, they were not equipped for sweeping moored or magnetic mines. Their work was to locate individual mines and neutralise them. This was a then-new role, and the class was configured for working in the shallow water of
river
A river is a natural flowing watercourse, usually freshwater, flowing towards an ocean, sea, lake or another river. In some cases, a river flows into the ground and becomes dry at the end of its course without reaching another body of ...
s,
estuaries
An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environme ...
and
shipping channel
In physical geography, a channel is a type of landform consisting of the outline of a path of relatively shallow and narrow body of water or of other fluids (e.g., lava), most commonly the confine of a river, river delta or strait. The word is ...
s.
The class consisted of 93 ships, launched between 1954 and 1959. was the first. They were built in three slightly different sub-groups, the first sub-group, the 26-group, is distinguished by
pennant number
In the Royal Navy and other navies of Europe and the Commonwealth of Nations, ships are identified by pennant number (an internationalisation of ''pendant number'', which it was called before 1948). Historically, naval ships flew a flag that iden ...
s 26xx, and the second and third sub-groups, the 27-group, are distinguished by pennant numbers 27xx. The 26-group was of wood and
non-ferrous metal
In metallurgy, non-ferrous metals are metals or alloys that do not contain iron ( allotropes of iron, ferrite, and so on) in appreciable amounts.
Generally more costly than ferrous metals, non-ferrous metals are used because of desirable prop ...
composite construction and the 27-group was of all-wood construction. The third sub-group is distinguished by a prominent rubbing strake around the hull and slightly larger dimensions.
The vessels displaced fully laden and were armed with one
40 mm Bofors or
20 mm Oerlikon gun. They were long overall with a beam. The construction was of wood to minimise the magnetic signature. The crew complement was 15, rising to 22 in wartime.
The engines of this class were
Paxman diesels, some of which were built under licence by
Ruston and Hornsby of
Lincoln. Each vessel had: two 12YHAXM (intercooled) for main propulsion, rated at at 1,000 rpm, plus one 12YHAZ for pulse generation. Maximum speed was dropping to when mine sweeping.
The class shared the same basic hull as the and the inshore survey craft.
Ships
* (IMS87)
* (IMS02)
* (IMS03)
* (IMS04)
* (IMS05)
* (IMS06)
* (IMS85)
* (IMS07)
* (IMS08)
* (IMS09)
* (IMS10)
* (IMS11)
* (IMS12) (later HMMS ''Temasek'')
* (IMS13)
* (IMS14)
* (IMS15)
* (IMS16)
* (IMS17)
* (IMS18)
* (IMS19)
* (IMS31)
* (IMS21)
* (IMS22)
* (IMS23)
* (IMS24)
* (IMS25)
* (IMS26)
* (IMS27)
* (IMS28)
* (IMS29)
* (IMS30)
* (IMS54)
* (IMS20)
* (IMS32)
* (IMS88)
* (IMS33)
* (IMS34)
* (IMS35)
* (IMS36)
* (IMS37)
* (IMS42)
* (IMS39)
* (IMS01)
* (IMS40)
* (IMS41)
* (IMS38)
* (IMS43) (burnt to hull, London 2017)
* (IMS44)
* (IMS45)
* (IMS89)
* (IMS46)
* (IMS47)
* (IMS48)
* (IMS49)
* (IMS50)
* (IMS51)
* (IMS83)
* (IMS52)
* (IMS53)
* (IMS55)
* (IMS56)
* (IMS92)
* (IMS82)
* (IMS81)
* (IMS57) (later HMS ''Waterwitch'')
* (IMS58)
* (IMS84)
* (IMS59)
* (IMS86)
* (IMS60)
* (IMS61)
* (IMS62)
* (IMS91)
* (IMS64)
* (IMS63)
* (IMS65)
* (IMS66) (beached and abandoned, Battersea London 2017)
* (IMS68)
* (IMS67)
* (IMS69)
* (IMS70)
* (IMS90)
*
* (IMS71)
* (IMS72)
* (IMS73)
* (IMS74)
* (IMS75)
* (IMS76)
* (IMS77)
* (IMS78)
* (IMS79)
* (IMS80) (later HMS ''Woodlark'')
In 1964 Ten of the vessels were allocated to the
Royal Naval Auxiliary Service
The Royal Naval Auxiliary Service (RNXS) was a uniformed, unarmed, civilian volunteer service, administered and trained by the Royal Navy to operate in the ports and anchorages of the United Kingdom in an emergency. Although the abbreviated title w ...
References
* ''Warships of the Royal Navy'', Captain John. E. Moore RN, Jane's Publishing, 1979
{{Ship classes of the Indian Navy
Mine warfare vessel classes
Ship classes of the Royal Navy
Mine warfare vessels of the Yugoslav Navy