New Tug for Pacific Tug Pty Ltd of Brisbane Australia.

by Hans | July 25th, 2011

Shipco Marine Constructors deliver their latest new build 15m tug PT May for sea trials and testing.

This is the first small tug of this type to be built in New Zealand for some time, standing out from its predecessors with a number of clever design features and performing more like a z drive ship handling tug than a workboat.

Utilising independent steerable nozzles the tug has exceptional manouverability including being able to move sideways, which is a step ahead from most standard twin screw tugs. With 1200 hp giving 17t ahead and 14t astern bollard pull this makes for a very powerful and lively vessel that can be used to best advantage with fingertip control.

Bollard pull trials ahead and astern went without a hitch, the tug performing very well with minimal vibration, easily maintaining position and heading. Compared to existing tugs with hard mounted propulsion machinery PT May is a pleasure to operate, the engines being soft mounted with flexible couplings to hard mounted gearboxes, providing a very smooth outcome, commented on by a good number of people. Noise is of an acceptable level for such a small steel vessel with a big power plant, insulation fitted to a high standard.

Once all trials were completed to satisfaction of the GL surveyor the tug was handed over to the owner, Pacific Tug, Australia. We then delivered the tug to Auckland, where a number of towing jobs of all types were carried out to trial the vessel further for both Pacific Tug and Shipco, while awaiting shipping to Brisbane. PT May performed above expectation on all towing and workboat duties identifying how easy these jobs can be undertaken with modern, properly designed equipment.

Eventually a ship was found for transport to Australia, Pacific Tug contracting us to deliver the tug  further down the coast to Tauranga. This voyage was carried out in less than ideal conditions, 25-35 knot wind and rough seas. The sea keeping ability of this little tug is exceptional and gives the feel of a larger vessel. We had a far more comfortable ride down the coast than we would have had in one of our larger tugs.

Fuel consumption free steaming appears to be very acceptable, 1700 rpm giving a solid average speed of 10 knots @ 94 LPH including gen set. In conclusion I feel that Shipco have developed an outstanding little tug that will be very suitable for a wide range of towing and workboat duties, being built and finished to a  high standard.

Principal particulars:

Length overall (excluding fenders): 15 Metres; Beam (moulded):  6.5 Metres; Depth (moulded):  2.75 Metres; Draft  Aft:  2.8 Metres; Fuel oil: 11.15 Cub M; Spare fuel oil: 10.04 Cub M; Fresh water; 3.04 Cub M; Sewage: 2.66 Cub M; Dirty lube oil:  2.59 Cub M; Clean lube oil: 1.3 Cub M;

Hull and Machinery design by : SHIPCO

Classification : Germanisher Lloyd :   notation ( +) 100 A5  RSA (200) TUG  MC

Safety, Lifesaving and navigation  equipment : Australia CLASS 2B

Built For : Pacific Tug Pty Ltd – Brisbane  Australia

Trials Performance : Bollard Pull  ahead  17 tonnes –  astern  14 tonnes; Speed  : 10.5 Knots; Normal Manning   2 Persons; Crew accommodation for 4 persons.

For crew comfort the wheelhouse and  accommodation floors are floating type, the engines are resiliently mounted with the main engines being on LOREZ  spring type vibration isolators, Exhaust piping and mufflers are  resiliently amounted all resulting in very good noise control. Air conditioning  of the wheelhouse and accommodation areas are by Ocean Breeze using a chilled  water system with the keel cooledchiller units in the engine room and the  stainless steel air handlers in the living areas.

Generater sets Electrical power is generated  by two Cummins generator sets; One set: 6B-CP80DM/5 rated 80 KW 380  volts 50 HZ  Keel cooled electric started; One set :6C-CP136DM/5 rated 136 KW  380 volts 50Hz keel cooled air started. This set supplies the power necessary  to drive the towing winch.

Fendering system  : by SHIPCO

Around the bow and extending to the  forward shoulders is a 1.1metre wide sweep of double loop tyre fendering 500mm  deep. This fendering  has very good  energy absorbing characteristics together with good holding abilities. Aft of  this is a section of aircraft tyres  1.00  metre dia 500mm wide secured to the hull without chains by way of steel rims.  Aft of this are two rows of veregated  single cut tyre fenders suitable for hard knocks that inevitably happen.

Towing winch—Manufacturer  — SHIPCO

Electrically driven 37 Kw via an ABB variable speed drive Brake holding capacity 75 tonnes  hydraulic operation; Line pull bare drum 11 tonnes at 15  metres a minute; Line pull 4th layer 8 tonnes at  22metres per minute; Drum diameter 610mm capacity 550 metres x 32mm diameter wire in 6 layers; Level wind equipment installed Controlled emergency quick release  is provided at speeds of 48 to 88 metres per minute; The winch drive reductions are achieved  firstly via a planetry drive  with a reduction ratio of 25.6 to 1 then to a pinion and bull gear drive having  a 4.58 to 1 reduction. The winch control console is positioned on the engine casing deck forward of the winch. This console houses the winch control joystick, The hydraulic towing pins and hold down push  buttons, the steering jog levers and rudder indicators together with the engine and transmission control levers, allowing the winch operator full control.

The ABB variable speed drive uses ABB’s own direct torque control algorithm giving very smooth acceleration and deceleration to required speeds and providing for simple setup of user selected line speed and pull from 0 to 100% of winch capacity. The system incorporates the brake control features and does not release the brake until the drive has generated suffecient force (typically about 50%)  against the brake before releasing it. These low harmonic electrical drives are built to class approval and are provided with special filtering achieving normally less than 5% current distortion.

Towing pins and stern roller Manufacturer  — SHIPCO

Pins are electric/hydraulic operation 3 pin type with hold down. Each hardened pin slides up and down in bronze bushes and  rotates on 4 roller bearings for each pin. The wire hold down lug is raised up and  folded down hydraulically. The 400 mm dia stern roller is balanced, running in spherical bearings and has a SWL of 35 tonnes.

Capstan Manufacturer  — SHIPCO

Hydraulically driven  vertical type 500mm dia waist giving a 5 tonne pull at 20metres per minute. Foot switch operation.

Tow Hook Manufacturer   —SHIPCO

35 tonne SWL rotating hook type with hydraulic release.

Propulsion Main engines are 2 off Cummins KTA 19 –M3 rated 600 BHP each at 1800 rpm, air started and keel cooled. Driving through ZF island mounted gearboxes model W 1800 ratio 6.160 to 1 and connected to the engines via a Centa CX-55-LFS2 input coupling. Propeller shafts are of mild steel running in oil lubricated bronze bushes with 1494mm dia 4 bladed propellors with a 20 degree blade skew and made from Manganese bronze. Engine and gearbox control is by a 3 station ZF  controller with 1 MC2000 and 2 760 control heads. The propulsion train is remarkably free of vibration in both ahead and astern travel and at all speed ranges.

Steering:

The excellent manouverability of the tug is obtained from the specially designed independently steerable nozzles. The nozzles are top hung and have 35 degrees of steerage to port and starboard in a total of 12 seconds.Steering gear is of SHIPCO manufacture  with TQM auto pilot and electronic steering levers.Three steering stations are provided, one in the wheelhouse, one on the flybridge and one at the winch station.

Kelvin Hardie
PO Box 24 Whangarei, New Zealand 0140
PH: +649 4382219
Fax: +649 4387845
www.shipco.co.nz

Related Posts:

Leave a Reply

Alphatron Marine
Transport & Offshore Services
Sanmar Denizcilik A.?
Van Wijngaarden Marine Services B.V.
Damen Shipyard Group
DMT MARINE EQUIPMENT
Robert Allan Ltd
W.K.M. Cornelisse Trading B.V.
Astilleros Armon
Bogazici Shipping
Sea Conquest Marine Surveys & Consultancy