Robert Allan Ltd.’s 150th Sanmar-built Tug for Svitzer’s Silver Bullet Project

March 30, 2017

The Svitzer Hermod and Svitzer Chirripo are the first two of six customized Robert Allan Ltd. RAstar 2800 class terminal support/escort tug designs for Svitzer’s “Silver Bullet” fleet replenishment program. Svitzer Chirripo will be the 150th tug that Sanmar Shipyards has built to a design by Robert Allan Ltd., a significant milestone for both companies.

The co-operation between these two companies began in 1995, with a series of small 18 m tugs designed and built for Sanmar’s own fleet. Their collaboration has since grown to include several classes of tugs, from the high performance RAstar escort tugs, through the workhorse RAmparts class, to the innovative VectRA VSP tug design. Ranging in size from 15 m to 34 m, these tugs have been delivered all over the world; from Australia to Canada to Europe, the Middle East and all points between.

The first vessel is named after Hermod, son of Odin, often considered the “messenger of the gods” in Norse mythology.

These new vessels have been fully customized to suit the client’s very specific operational requirements, and have been classed to the following notation:



  • Length overall: 28.2 m
  • Beam, moulded, extreme: 12.6 m
  • Depth, moulded (hull): 5.3 m
  • Maximum draft: 4.12 m

Major tank capacities

  • Fuel oil: 112 m3
  • Potable Water: 14 m3
  • Foam: 4 m3

On trials, the tugs met or exceeded all performance expectations, with the following results:

  • Bollard Pull, ahead: 70+ tonnes
  • Free running speed, ahead: 13.5 knots

The vessels have been arranged and outfitted to a high standard with eight crew berths in total. The Officer’s cabins are located on the main deck and three private double crew cabins are located on the lower accommodation deck. A fully appointed mess/lounge and a modern fully-equipped galley are also located on the main deck.

The tugs are designed to provide ship handling and ship assist work performed over the bow utilizing a hawser winch and staple. Towing operations are performed off the aft deck using a quick release towing hook / tow post.

The wheelhouse is designed for maximum all-round visibility with a forward control station providing maximum visibility to both fore and aft deck working areas.

Main propulsion for each tug comprises a pair of MTU 16V4000 M63 diesel engines, each rated 2000 kW at 1800 rpm, and each driving a Schottel, SRP 460 (ex. SRP 1515) fixed pitch Z-drive unit with 0-idle slipping clutch, in ASD configuration.

The electrical plant comprises two (2) identical diesel gen-sets, each with a power output of 100 ekW.

Ship-handling fenders at the bow consist of one row of cylindrical fender at the main deck level, 800 mm OD x 400 mm ID. A 300 mm thick “W” block fender is arranged below the cylindrical fender. Two strakes of 300 x 300 hollow “D” fender provides protection at the main and foc’sle deck sheer lines, and a 300 mm thick W-fender is used at the stern.

Robert Allan Ltd. continues to enhance the designs of its RAstar high-performance Escort Tug series.. Designed primarily for terminal work, these tugs feature foil-shaped escort skegs and a sponsoned hull form, which together have been proven in both model and full-scale testing to provide significantly enhanced escort towing and seakeeping performance. Roll motions and accelerations are significantly less than those of comparable sized “standard” tug hulls.

Robert Allan Ltd is very pleased to continue to provide our design expertise to these two highly valued and respected companies and to support the construction of this new flotilla of very capable towing vessels.

For more information on the Svitzer Hermod, Svitzer Chirripo or any of the RAstar 2800 tugs, or on any other high-performance vessel designs developed by Robert Allan Ltd., please contact us at

General Arrangement