D-8 



SL 3 



Function : Pipe trenching. Pipe diameter - 50cm to 120cm (20 in. to h'J in.) 



Trench depth - 1.5m (U.9 ft) (depending on pipe diameter). 



Operating Depth : 50m (l6H ft) Minimum depth - 5m (l6 ft) 



Dimensions (LxWxH) : 6m x Tm x 6m (20 ft x 23 ft x 20 ft) 



Weight (Dry) : l6t ( l8 tons), in water - 8t (9 tons) 



Speed : a) Pipe CD - 0.5m (1.6 ft), trench width 2m (7 ft). Speed: 72m/hr 



(236 ft) 



b) Pipe OD - 1.0m (3 ft), trench width 2.5m (6.2 ft). Speed: 58m/hr 

 (190 ft) 



c) Pipe OD - 1.5m (i+.9 ft),' trench width 3m ( 10 ft). Speed: l+8m/hr 

 (158 ft). 



Power: Jetting power supplied "by two, 150 KVA generators UU0/380 V, 



50 Hz, powering four 30hp each Eobot pumps on the vehicle. Four, 600 cfm 



compressors. 



Propulsion: Towed by surface barge. The SL 3 is a sled-type machine which 



straddles the pipe and is supported on the seabed by tubular skids. To 



guide the machine along the pipe are two side rollers at each end, one 



on either side of the pipe and two top rollers, one at each end. 



Tools/Instrumentation : Four electrically driven pumps, provide 



pressurized water to water jets which fluidize the bottom sediment. The 



sediment is then removed and deposited away from the trench by airlift 



educators. Vehicle instrumentation includes a device to measure machine 



angle across the pipeline, water jet and air pressure indicators and 



amperage readings for water pijmp. 



Shipboard Components: See "Power" for components. 



Support Ship Requirements: Specially designed and dedicated barges 



support the operations of SL 3. The capabilities of one of these barges 



are presented in the description of TM III 



Status: Operational 



Builder/Operator : Land and Marine Engineering Ltd. 



Merseyside, England 



