The dynamically positioned trenching support vessel Calamity Jane assists Solitaire, Audacia and Lorelay with activities such as pre- and post route surveying, crossing preparation and mattress installation. She also operates as an independent unit with Allseas' unique mechanical trencher Digging Donald.
To date, Digging Donald has trenched nearly 3,300 km of pipeline worldwide, up to a diameter of 42", in soil conditions ranging from loose sand to very hard clay.
Calamity Jane
-
Length overall
151 m (495 ft) -
Length between perpendiculars
117.2 m (384 ft) -
Maximum speed
11 knots -
Accommodation
72 persons -
Installed power
15,086 kW -
Dynamic positioning system
NMD Class 2 / LR DP (AA), type Alstom Cegelec 2 x DPS 902 Duplex system -
Cranes / lifting equipment
General purpose crane:
26 t (57 kips) at 31.33 m (103 ft)
Trencher handling frame:
170 t (375 kips) at 395 m water depth (1,296 ft)
A-frame on SB side:
35 t (77 kips) at waterline; 20 t (44 kips) at 1,570 m (5,151 ft); 5 t (11 kips) at 3,100 m (10,170 ft)
A-frame on PS side:
3.2 t (7 kips) at 3 m (10 ft)
Knuckle boom crane:
10 t (22 kips) at 3.5 m (12 ft)
Digging Donald is a crawler capable of trenching pipelines with an outside diameter of up to 42" in a variety of soil types. Depending on soil conditions, the machine can achieve a net trench depth of 2.1 m (7 ft) from the original seabed level by using mechanical digging arms and multi-pass jets.
Digging Donald is the only mechanical pipeline trencher never to make physical contact with the pipeline. It is fully remote controlled from on board Calamity Jane, and can operate at depths of up to 350 m (1,150 ft). It receives electric power via an umbilical; the same umbilical transmits observation signals to the vessel for processing.
Operational modes include trenching, jetting, backfilling and survey.
Digging Donald
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Length
17.7 m (58 ft) -
Width
9.6 m (32 ft) -
Height
6.7 m (22 ft) -
Maximum water depth
350 m (1,150 ft) -
Maximum speed
500 m/hr -
Installed power
1,000 kW (1,341 hp) -
Maximum pipeline diameter
42" O.D.
