| Minesweepers |
Commissioned at Vancouver April
2, 1942, HMCS Caraquet
was built for the Royal Navy and
transferred to the RCN. Caraquet
served on the West Coast from
May 1942 to March 1943, on the
East Coast from May 1943 to February
1944 and on the English Channel
for invasion duties. |
| National
Archives of Canada, PA-125863. |
|
Since WWI, Germany's warships and submarines
had enough autonomy to lay mines along both
the American and European Atlantic shores.
In 1939, when war became imminent, the Allies
feared they might face extensive minefields
blocking their harbours and threatening sea
routes. At that time, the Royal Canadian Navy
(RCN) had only four minesweepers: HMCS Comox,
Fundy, Gaspe and Nootka. The situation was
an emergency and called for a rapid response.
The Canadian Government authorized the construction
of Bangor class minesweepers. Like corvettes,
these were ships with a light draught, that
did not require the same degree of shipbuilding
expertise as cruisers and destroyers did.
They could be built in inland shipyards, along
the St. Lawrence and the Great Lakes.
The RCN will have up to 54 Bangor class minesweepers;
since the threat from German mines never reached
the expected level, many were used to escort
convoys along the Atlantic coasts and in the
Gulf of St. Lawrence. Later on, German mines
will be a threat along the coats of Normandy
in June 1944, and Canadian minesweepers will
work together with the Royal Navy to clear
the Channel.
|
| Diagram:Minesweeping |
|
Canadian shipyards also built an improved
version of Bangor class vessels, known as
the Algerine class. There were 41 such ships
built in Canada, mostly at the Port Arthur
shipyards. Of that number, only 12 served
in the RCN; they were used as escort ships,
and did not carry minesweeping gear.
Minesweeping Techniques
| |
|
German
contact mine in waters off Nova
Scotia, 2 June 1943. |
| |
Photo
by H.H. Black. Department of National
Defence / National Archives of
Canada, PA-178962. |
|
Contact mines are anchored to the ocean
floor with cables that keep them floating
just beneath the surface. To neutralize
them, the mooring cable must first be severed,
to allow the mine to bob up and become visible.
Minesweepers drag along a steel wire that
ends with a torpedo-shaped floater. Not
far from the floater is a steel frame with
angled fins, called the "otter"
that keeps the wire under water at the proper
depth as the minesweeper moves along. The
wire is fitted with cutters. When a mine
cable touches the wire, it slides along
it until it hits a cutter. As the cable
breaks, the mine is freed and bobs up to
the surface. It must then be destroyed by
firing at it with guns or rifles. This is
known as the "Oropesa" technique.
Minesweepers also have an electrical system
used to reduce their magnetic field, in
order to avoid detonating magnetic mines.
Other devices were used to create a field
strong enough to detonate mines at a distance.
Against acoustic mines, minesweepers used
a sound-making machine made of a hammer
hitting on a case.
| Minesweepers
|
| |
Bangor
class |
Algerine
class |
| Length |
54.9
m |
68.6
m |
| Width
|
8.7
m |
10.8
m |
| Draught |
2.6
m |
2.6
m |
| Displacement |
672
tonnes |
990
tonnes |
| Maximum
Speed |
16
knots |
16
knots |
| Armament |
One
12 pound (5.44 kg) gun at the foreTwo
20 mm Oerlikon guns 40 depth charges,
launchers on both sides, rails at the
stern |
One
4-inch gun at the foreFour 20 mm Oerlikon
guns One "Hedgehog" Depth
charges, launchers on both sides, rails
at the stern |
| Crew |
83
men |
107
men |
|
| Suggested
Reading: |
Ken Macpherson
and John Burgess, The Ships of Canada's
Naval Forces 1910-1981, A Complete Pictorial
History of Canadian Warships, Collins,
Toronto, 1981.
Ken Macpherson and John Milner, Minesweepers
of the Royal Canadian Navy 1938-1945,
Vanwell, St. Catharines (Ontario), ca.
1990.
|
|
| Links: |
| For detailed description
of WWII mines and minesweeping techniques,
see "Mine
Warfare", by Roy Cordell |
| For specifications of Canadian
minesweepers, see the Haze
Gray and Underway site |
| For a photograph and description
of all Canadian warships, see the site
of the Manitoba
Naval Museum |
|
Next:
Frigates 
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Canada in WWII
