Michelle Sloan – A RAmparts 2400 addition to Harley Marine Services tug fleet

April 29, 2015


On March 26th 2015, Harley Marine Services took delivery of the first of two new “enhanced” RAmparts 2400 ASD tugs, at their world headquarters in Seattle, WA. This powerful new tug is named the Michelle Sloan in honour of a courageous woman who lost a 12 year battle with breast cancer last year. Built at Diversified Marine Inc. (DMI) in Portland, Oregon, the Michelle Sloan truly shows off her builder’s pride in quality construction.

The Michelle Sloan is the latest of the RAmparts 2400 design from Robert Allan Ltd. and is an evolution of Harley Marine Services’ existing tugs Tim Quigg and John Quigg also built by DMI in 2004. The new tug has a wider hull, increased BP performance, improved crew accommodations, and a modified skeg. Particulars of the Michelle Sloan are as follows:


Length overall:
Beam, moulded, extreme:
Depth, moulded (hull):
Maximum draft:
Gross Tonnage:
– 80’-0”
– 36’-0”
– 16’-8”
– 17’-5”
– <200 GRT (US Tonnage)


The tug was designed and constructed to satisfy all applicable Rules and Regulations of USCG and meet or exceed the minimum scantling requirements of any Classification Society.


Tank capacities are as follows:

Fuel Oil:
Potable Water:
Main Engine Lube Oil:
Sludge Tank:
Grey Water:
Emergency Black Water:
– 32,800 Gals.
– 2,900 Gals.
– 410 Gals.
– 890 Gals.
– 830 Gals.
– 275 Gals.


Trials results were as follows:

Bollard Pull, ahead:
Bollard Pull, astern:
Free running speed, ahead:
– 69.0/71.3 Short tons
– 65.4/67.4 Short tons
– 12.5 knots


The vessel has been outfitted to the highest standards for a normal operating crew of 2, with accommodations for up to six persons. The Master’s cabin is located on the main deck, with two additional double crew cabins located on the lower accommodation deck. There is also a galley and mess room located on the main deck.

The deck machinery comprises a Markey DEPC-48 render-recover type ship assist hawser winch on the bow, spooled with 500 ft of 9” line, and a Markey DEPC-32 towing winch aft with a capacity of 250 ft of 6-1/2” line. In addition, a capstan is installed on the fore deck to facilitate line handling operations.

The raised forecastle and elevated wheelhouse ensure good all-round visibility of the working decks and when handling large barges with high freeboard. This higher freeboard feature also provides a high standard of sea-keeping when working in exposed waters, but is also configured so as not to impede the ability of the tug to work closely under the flare of the newer generation of large ships.

Main propulsion for each tug comprises a pair of CAT 3516C diesel engines, each rated 2,575 bhp at 1600 rpm, and each driving a Rolls-Royce US 205 Z-drive unit, with a 94.5” diameter fixed pitch propeller.

The electrical plant consists of two (2) identical CAT C6.6 diesel gen-sets, each with a power output of 125 ekW, 60 Hz.

Ship-handling fenders at the bow consist of one tier of 36” OD x 18” ID cylindrical fender at the main deck level, with 12” loop type Schuyler fenders between the main deck and the knuckle, 11” laminated bow fenders below, and 12” hollow D style fenders along the stem and skeg. Tires and 8” hollow “D” fender provide protection at the main and forecastle sides and sheer lines, and 12” loop type fendering is used at the stern.

For more information on the Michelle Sloan, the RAmparts 2400 Class tugs, or on any other high- performance vessel designs developed by Robert Allan Ltd., please contact design@ral.ca.