Damen’s ‘Stan Tug’ range takes a big step forward

The development of the well-known ‘Damen Stan Tug’ range of tug-workboats has a history that dates back to the formation of Damen Shipyards as we know it today. In those early days, commencing in1969, among the most important products selected as ‘standard’ designs for serial production were the Pushy Cat and original versions of the Stan Tug. The Pushy Cat and the Stan Tug 1 became extremely popular, particularly in the dredging and marine construction industries. Early examples of both are still in operation and are a tribute to those original designs.

Although over four decades Damen has evolved into a massive shipbuilding group, it maintains a very close relationship with its clients in the towage, dredging and marine construction industries. In that way the company continually reacts to feedback from its customers and progressively refines established designs and introduces new vessels to meet the operators’ demands. That is especially true of the Damen Stan Tug range in which almost every vessel has been replaced or modernised in recent years.

The smaller tug/workboats in the Stan Tug are the latest vessels to receive the attention from the Damen Tugs & Workboats project team. After careful studies and market research it was decided to discontinue the Pushy Cat 1204 series and the Stan Tug 1404 and offer one brand new design in their place, the Damen Stan Tug 1205.

The new Stan Tug 1205 design has benefited greatly from the considerable knowledge and experience gained while producing the new Stan Tug 1606 and Stan Tug 1907. Both were developed from earlier highly successful vessels built by Damen in large numbers. Many features inherent in the Stan Tug 1606 in particular have been incorporated in the new 12m tug/workboat. During the design process all of the following matters were addressed; hull design, including full scale testing and calculations for structural strength, fatigue, natural frequencies and wave profile; optimisation of the propulsion system; noise levels and speed and bollard pull performance.

As a direct result of that work the Stan Tug 1205 evolved, a small, very compact and powerful vessel with clean lines and many of the distinctive features in common with its larger sisters. In its basic form the tug/workboat is designed to carry out towing, mooring, transportation of passengers and pilotage duties. The first vessel was completed in late 2009 and has been subjected to extensive trials and testing all of which confirmed and in many cases exceeded expectations.

The Stan Tug 1205 is a twin-screw vessel, measuring 13.08m in length overall, with a maximum beam of 5.28m, a depth (at sides) of 2.30m an approximate draft (aft) of 2.00m and a displacement of approximately 55 tonnes. Under Bureau Veritas rules the vessel is classed 1+HULL. MACH, Seagoing launch.

An all welded steel hull is of rugged single chine construction using 10mm thick plate in the sides and bottom and a 15mm sheerstrake. The hull form is based on that of the Stan Tug 1606 and incorporates a heavily built push knee in the bow and a smooth water flow to the propellers and nozzles. Incorporated in the hull structure are internal tanks capable of a accepting 5.5 cu/m of fuel, 0.35 cu/m of fresh water, 0.32 cu/m of sewage and 0.30 cu/m of bilge water.

The decks, fore and aft, have been kept as clear of obstructions as possible to provide a safe working environment – with maximum available space. Substantial bulwarks of 1m in height around the fore deck are reduced in height aft and incorporate access doors. Bulwark height can be chosen to suit operating conditions and national regulations. Mooring bits, the engineroom hatch and the exhaust outlet housings are neatly built in and tank vents, and other necessary protrusions, are guarded to prevent fouling. In common with all of the smaller Damen workboats, lifting eyes are provided on deck in four locations. The design of all deck fittings is intended to improve safety and simplify maintenance.

A single anchor is housed beneath the starboard bow and handled by a very compact electrically driven windlass operating on a 24 volt supply.

Fendering is intended to afford good protection when towing and working alongside other craft. The push knee is heavily fendered with cylindrical rubber mouldings and a ‘D’ section moulding is fitted all round the vessel at deck level. Towing gear comprises ‘H’ style towing bitts, carrying a Mampaey quick release tow hook with a safe working load of 15 tonnes.

The Damen Stan Tug 1205 is suitable for use as a mooring boat and for pilotage duties. When used to handle ship’s mooring lines overhead protection rails can be fitted, along with bulwarks of a suitable height and any other necessary fittings. For transporting pilots additional handrails, steps, and other essential equipment is easily installed.

At the heart of this new tug/workboat is a rugged propulsion system based on Damen’s experience with the larger Stan Tug 1606. Two heavy duty, manganese bronze, Kaplan style fixed pitch propellers of 1050mm in diameter, rotate within high performance Van der Giessen ‘Optima’ thrust augmenting nozzles lined with stainless steel. The stainless steel propeller shafts are water lubricated at the outboard end and the inboard bearings with grease. Two streamlined ‘double plate’ rudders, one aft of each nozzle, are operated by a powered hydraulic steering gear giving 2 x 55 degrees of movement.

Two Volvo D9 MH, diesel main engines generate a total of 644bhp (442bkW) at 1800 rev/min to drive the propellers via Twin Disc MG 5091, reverse reduction, gearboxes with a ratio of 3.82:1. These are clean ‘state of the art’ diesels complying with the requirements of IMO and US EPA Tier 2. They are compact, rugged engines, equipped with electronic fuel injection systems and twin turbo chargers, giving them outstanding acceleration and economy. Flexible mountings and couplings are used to reduce vibration and noise transmission throughout the vessel.

A well-proven closed circuit keel cooling system is utilised enabling the vessel to operate in extremely shallow water without fear of contamination. Exhaust gases are discharged through the transom, via 40 dBA silencers, well lagged and mounted in the engineroom. An engineroom ventilation system provides 7000 cu/m of air per hour. An engineroom alarm is installed and activated by engine and gearbox fault conditions and bilge water sensors.

Electrical power is supplied by a single Onan MDKBP-eQD auxiliary generator rated at 17.5kvA at 230 volts, 50 Hz. Two 24volt 200Ah battery packs, with a changeover facility is used for engine starting and domestic use.

An electrically driven Sterling SIHI VWSI5013 bilge and general service pump is rated at 15 cu/m of water per hour and has hydrant connections in the engineroom. An emergency, hand operated bilge pump is located on deck.

The wheelhouse design for the new Stan Tug 1205 follows closely the standards developed for the larger vessels in the series. It has a modern efficient layout with the controls and instrument panels positioned using ergonomic principles. Excellent all round visibility is made possible by large, deep, windows and few ‘blind spots’. A centrally located helmsman’s position, and chair, is placed close to the forward windows, with all of the essential controls and instruments within easy reach. A standard instrumentation outfit includes a Fluxgate compass, a Furuno GP-32 GPS, a Furuno LS 6100 echosounder and Sailor RT2048, 25W VHF radio. Mandatory modern LED navigation lights, towing and pilot lights, and a searchlight are also standard items. Additional equipment such as a Furuno FR 1832 radar are optional extras.

Comfortable seating for two persons and a table are part of the standard wheelhouse layout. An important feature of the wheelhouse design is the flexible mounting of the entire structure. Modern durable linings and insulating materials are used throughout and a ‘Dampa’ acoustic ceiling is fitted. The result of this incredible attention to detail is a massive reduction in sound levels in the wheelhouse to a figure of just 55dBA when the vessel is underway.

Both the wheelhouse and additional living facilities below decks are airconditioned and heated. The standard basic workboat is fitted out as a ‘day boat’ with cooking facilities, a refrigerator, pantry, shelving and a toilet with hot and cold water. As an option, the same area below deck can be fitted out to include sleeping accommodation for two persons.

On trials, the first Stan Tug 1205 surpassed even the most optimistic expectations of the design team. The vessel handled extremely well, and was vibration free and extremely quiet. A bollard pull of 9.0 tonnes was achieved and a free running speed of 9.8 knots.

This first vessel is one of a batch of six, all of which will be fully fitted out ready for delivery. Most additional items can be supplied from stock, including a deck crane and additional fire fighting equipment. Even with a degree of customisation to suit a client’s particular needs delivery can normally be made within 8 weeks of placing an order.

Two other vessels currently under development for the smaller end of the Stan Tug range are the Stan Launch 804 and the Stan Tug 1004. These new vessels, which will be available shortly, will be offered as replacements for the Mini Cat 803 and where suitable the Pushy Cat 1204. Once again both vessels are recognisable at part of the new ‘Stan Tug’ tug/workboat family and have many design features in common with their larger relations.

The Damen Stan Launch 804 is a very compact and versatile single-screw boat capable of undertaking towing and mooring operations. A vessel of 8.44m in length and beam of 3.52m, the launch is powered by a Volvo DS TA/1 diesel generating 121bhp (89bkW at 1900 rev/min. Power is transmitted to a single ‘open’ propeller to give an estimated bollard pull of 1 tonne and a speed of 6 knots.

The larger Damen Stan Tug 1004 has many features common to the Stan Tug 1205 but is a single screw vessel of just 10.67m in length. It is ideally suited to mooring, towage and pilotage duties. A Volvo D9 MH main engine produces 296 bhp (221 bkW) at 1800 rev/min. The single propeller rotates in a fixed ‘Optima’ nozzle and twin high performance rudders will make this a very agile craft. A bollard pull of 4.1 tonnes is anticipated and a maximum speed of 8.3 knots.

Both of these small single-screw vessels are under construction and will soon be available from stock.

Eleven designs now make up the Damen Stan Tug series. Five of the smaller Stan Tugs, ranging from the new Stan Launch 804 to the established Stan Tug 1907, offer operators a series of modern tug/workboats with bollard pulls of between 2 and 27 tonnes. For harbour, offshore and coastal towing Damen offer three vessels, the Stan Tug 2208, Stan Tug 2608 and the Stan Tug 2909 all of which are popular designs with bollard pulls of between 40 and 65 tonnes. Finally three larger Stan Tugs, the Stan Tug 3509, Stan Tug 4011 and Stan Tug 4511 are designed for offshore, coastal and deepsea towing activities with bollard pulls of 67, 90 and 100 tonnes respectively.

As previously mentioned the Damen Stan Tug Series has a history of more than 40 years and benefit greatly from continuous improvements, based on the considerable knowledge and experience gained from our customers.