"BUSTLER"
and 
"POWERFUL")Bridge Control
Duty tug from 1600 -0730 every night of the year
| Dimensions in metres | 38.8 x 9.4 x 4.3 |
| Power | 1320 BHP x 2 = 2640 BHP |
| Speed | 12 knots |
| Bollard Pull | 28 tonnes |
2 x Lips Fixed Pitch Propellers in High-Lift Nozzles. Triple
Shutter Hi-Lift Rudders behind each Nozzle.
| Dimensions in metres | 21.3 x 7.6 x 3.4 |
| Power | 1050 BHP x 2 = 2100 BHP |
| Speed | 12 - 15 knots |
| Bollard Pull | 33 tonnes |
Conventional Twin Propeller and twin rudder Bridge Control
| Dimensions in metres | 28.7 x 7.5 x 3.8 |
| Power | 650 BHP x 2 = 1300 BHP |
| Speed | 10 knots |
| Bollard Pull | 16 Tonnes |
"GWENDOLINE
P ", "GENEVIEVE", 
"HELEN")Single unit Voith Schneider Propeller
| Dimensions in metres | Length 22 m Draft 3.4 m |
| Power | 615 BHP |
| Speed | 9 knots |
| Bollard Pull | 5.7 tonnes |
ADVICE ON THE USE OF ADMIRALTY TUGS
Voith Schneider Tugs. Voith Schneider Tugs are most manoeuvrable and have the ability to exert full thrust in any direction (i.e. ahead, astern or sideways), if secured on the hook because the pull of the tow will twist them straight. They can rapidly alter their direction of tow because of their ability to exert a sideways thrust. These tugs are excellent for use with a push - pull lashup because they have the ability to 'walk sideways' up to a speed of about 2 knots thereby keeping their direction of thrust at right angles to the vessel being assisted. They secure their sterns against the tow so that their propulsion unit (which is forward of the bridge) is clear of the tow and giving them the capability to steer.
Dog Class Tugs. Good general purpose medium power tugs. They can pull on a tow line, or secure nose to bow or stern in a 'push / pull lashup' to control movement on or off the jetty. Nevertheless these tugs are fairly large and must be given adequate time to secure before they can give assistance. They have bridge control and fast reactions but even they take time to manoeuvre when weight is on the wire as they not only have to alter course but also move around to alter the direction of pull of the tow.
- Brief all tugs on your intended plan before starting. Never assume that they know your drill from previous berthing / unberthing, because conditions will probably be different and the tug master may have changed.
- During a manoeuvre use clear, precise orders leaving out your own call sign if no confusion can arise.
- When using a tug's stern hawser, a bow tug should not be allowed to move more than 45° from right ahead whilst your vessel has appreciable way on. If he does, STOP and reduce way quickly to avoid girding.
- Before making any course alternations with a head tug secured, warn him i.e. I SHALL BE TURNING SHORTLY - LEAD ROUND TO PORT/STARBOARD.
- When making a sternboard provided sufficient time / sea room is allowed a 'dog 'tug can pass a bow line into your bow up to 4 to 6 knots and then remain close and on a slack line whilst the ship has sternway on ready to turn square as the way comes off to hold your slip off / on the jetty against strong wind. Remember to keep the tug fully informed of adjustments to course and speed during the approach to the berth. Avoid driving ahead onto the tug during the final stages.
- When tugs are towing from their towing hooks, their wires are to be taken to a slip whenever practicable. In a push / pull mode when a tugs wire is working over is bow the same precaution should also apply, but tugs will accept their wires onto a bollard should a slip not be available,
- When slipping a tow line, other than in an emergency, request the tug to 'stop pulling and prepare to let go', once she has taken the strain off, and positioned herself to recover the tow without risk she will indicate 'I am ready to let go'. Only in an emergency should the tug be slipped with the strain on.
- The danger of girding arises when a tug is towed broadside by her own tow rope and is unable to manoeuvre out of this position. It may arise when the ship in tow gives a kick ahead or astern on her main engines. This is especially dangerous when a tug is towing on the beam and lack of judgement in such circumstances may manoeuvre the tug into a helpless position with danger of capsizing.
- Modern tugs have a large engine power in relation to their size and the strength of the tow rope is in proportion to the engine power. In consequence, if the tug is pulled laterally through the water with the tow rope bearing out on the beam it cannot be guaranteed that the tow-rope will part before the tug is capsized.
- Although tugs are provided with the slip hooks there is some likelihood of the slipping arrangement failing to function when the tow rope is bearing athwart the tug. In an emergency, Master and Mates in charge of tugs, who consider their vessel to be in danger of girding, have been ordered to slip the tow regardless of the situation of the vessel towed.
- It should be remembered that emergency slipping from a high freeboard ship with the wire under tension is liable to fling the towrope down on to the crew of the tug. Under normal conditions, when the towrope of a tug is to be slipped, the tension should be eased before the slip is knocked off. Whatever the tension in the towrope, the seaman knocking off the slip must stand well back and be prepared for either the slip, the towrope, or both, to fly up as the slip is released. The towrope, backed up on bollards, should be surged roundly under complete control, paying attention to the danger from it's bights or flakes on deck.
- The problem of girding does not apply to water tractors because their towing hooks are situated right aft and can swing through 360 degrees. Sudden acceleration by a ship under tow could result in a tractor being towed by the stern with the possibility of being pulled violently into the ships side. A tractor uses its propulsion unit to steer and consequently its forward speed is reduced when turning. Care must therefore be taken during a turn to avoid over running the tractors when used for towing ahead.
- The towing hooks of 'dogs and tractors' can accept ship's ropes passed down for towing. However it is admiralty practice to use approved towing hawsers, therefore only tugs hawsers will be used. Heaving lines however should always be ready for use.
