Some years ago I attended a Nautical Institute annual conference which was held in Aberdeen, what transpired got me thinking and this article was the result. 

There were a number of interesting presentations dealing with such things as BRM and HELM. By now we all know about Bridge Resource Management is, since it is usually flagged up by accident reports, but HELM was new to me and is Human Element Leadership and Management, and apparently it requires training. 

The Bibby Topaz in Aberdeen. Photo Jim Pottinger

One of the presentations was about the time in 2012 when the Bibby Topaz lost position due to a number of co-incident faults in the DP system, and one of the divers failed to get back into the bell because his umbilical was caught round a protuberance on the subsea manifold on which they were working. The ship rapidly lost position and the diver’s umbilical snapped, and it took some time for the mate and the master to get the vessel back to a point that they could recover the man, who was lying unconscious on top of the subsea structure.

The video of the event was of 45 minutes duration and featured the recovered diver with his newly built house and his wife. While this was heart-warming it took a question to a manager of the operating company to get an idea of what had happened, and frankly his explanation did nothing for me, because I have limited knowledge of DP systems. However I picked up the fact that it had apparently required the master and the mate to operate the controls because it was not possible for one man to do the whole job. Were they going to train their masters in ship handling, the manager was asked? Well, they were going to try.

Meanwhile at the conference, numbers of the presentations had variously discussed manual ship-handling, at least in part because of the resulting damage to ships and offshore installations when DP systems have failed. Also people had suggested to me, knowing of my interest in the topic, that ships were moving about the harbour in Aberdeen using DP. So there seems to be a need to promote ship-handling skills, but what to do? At the wash-up discussion I suggested to the panel that the Nautical Institute should take an action to positively promote manual handling training. The response was that it was part of their strategic plan. 

Whether having an item in the strategic plan to be actioned by 2021 is sufficient is doubtful. Heavens – by 2021 there may be no-one who actually knows how to drive a ship left. We are a dying breed. Some operators do not allow ships to be operated in manual control within their 500 metre zone. Some ships do not have their controls positioned in such a way that they can all be operated at the same time (Apparently including the Bibby Topaz). Typically some, or possibly all of the UT755s do not allow the person at the controls to operate the rudders. They are position out of reach of the driver when the chair is in the control position.

And it has also occurred to me that of the 170 odd people in the conference, only a few of those present would know how to drive a supply ship, so in a way this discussion is meaningless. What’s the difference? In an attempt to answer that question there follows an explanation of what might be involved.

The essential requirement of offshore ship handling is to maintain station within range of an offshore crane, so that cargo can be discharged and loaded and liquids and powders can be discharged by means of long hoses, The process has developed over a couple of generations of supply ship deck officers. Back in the early days the ships all tied up at offshore installations and in some areas of the world they still do. This only requires strong nerves and a technique for approaching the offshore object, although often the lack of capstans aft ensured some heart stopping moments.

But in the North Sea when it was too rough to tie up, but an urgent item of cargo was required, the installation would ask if they could “snatch” the lift, and so the master would attempt to get the ship under the crane and, if successful, the lift would be carried out before it drifted away. Later snatching became commonplace, and finally it became the usual means of working, incidentally turning the pipe carrier into the optimum PSV. The person driving would attempt to hold the ship in position by altering the thrust of the engines, the position of the rudders, and usually the power of the thrusters. 

When this situation became the norm the joystick was added to the canon of equipment available to the driver, and really in order to operate it more easily an additional thruster was often added forward, and a couple of thrusters aft. This reduced the complexity of going sideways using the engines and rudders. But the joystick is an aide and so the driver should be able to maintain station using the individual controls.

So no-one is saying that to drive a ship manually is easy. It’s not even easy to explain. But I’ll attempt it using an example.  In the mid 1990s I was captain of a Halter Marine 180 footer, one of a number working in the Saudi oilfields, and I was assigned to the “drilling group” which supplied and assisted with the operation of a number jack-ups out there. There were other groups of ships, some supplying GOSPs (Gas Oil Separation Platforms)and some supplying the self-propelled liftboats which maintained the smaller platforms. I got a call one day from the barge control, saying that while they knew it was nothing to do with me, could I go and give one of the liftboats water. When I got there I understood the problem. The liftboat was elevated next to a conductor – a pipe sticking out of the sea – rather than being alongside a platform, all of which have a landing stage. And as it turned out none of the ships in its support group could “snatch’ water. They all expected to tie up at the landing stage. 

So, it was a lovely day and I was able to determine that there was a slight current running, by looking at the legs of the liftboat, which I countered by crossing the engines – one ahead and one astern, and adjusting the rudders and the bowthruster. Once the position was stable I took down their hose and hovered about for an hour while our engine men pumped up the water. 

All I had to do was keep the hose slack, and avoid running into the legs of the liftboat or – God forbid – the conductor. If I perceived that the ship was drifting astern I would knock the ahead throttle a fraction, and take a bit of rudder off, if ahead I would do the same with the astern engine. If I perceived that the ship was drifting down current I would add a bit of rudder and bowthrust. All of these actions were extremely gentle, otherwise I would have to take some counter action once in the required position. 

So this was driving at the most basic level. I had been used to more sophisticated systems. Ulstein favoured rudder controls which allowed each to be operated separately allowing some drivers to turn them inwards, so that to go ahead on either engine would cant the stern over in the direction of that propeller. I preferred to keep the rudder on the astern engine amidships to increase the water flow to that engine and only use the rudder on the ahead engine. And of course, the presence of one or more stern thrusters makes the use of the rudders less essential since to go sideways only requires the use of the thrusters. And therefore if the ship is fitted with controllable pitch propellers it would be possible to use the main engines just for going ahead and astern. But necessarily the driver has to do more. I was once captain of a ship which had two stern thrusters, but we found that it habitually picked up bits of tree trunk in them in the River Dee, so it was easier to use the main engines and rudders for going sideways.

So what about azimuthing propulsion? I can almost hear you ask. And as a second question, why do so many ships with podded propulsion crash into things. It seems to me, as an observer, that it is thought by mariners that ships with podded propulsion are more difficult to steer, and therefore they tend to use the autopilot or the joystick for doing nearly everything, and then sometimes they forget that are using the autopilot, and worse, because they find that podded propulsion provides less directional control than conventional rudders they will increase the thrust, rather than disengaging the autopilot.  Check out the Big Orange XVIII at Ekofisk, a prime example.

Hence, driving a support vessel requires a thorough understanding of the forces to which the ship is being subjected and an understanding of the forces which the ship is capable of exerting. Even on very powerful ships windage is an impediment, and it should be born in mind that the most potent vessels have a job to make more than a couple of knots sideways, so current can be a problem. And if you question anyone who pays for simulator time you will find that it is used to exercise emergencies and as a simple teaching aide. No-one is going to give an individual the many hours of practice required to learn to drive as a reflex action. But obviously it can be done, and shipmasters and owners and charterers should bear in mind that their deck officers will all be keen to learn, so let them at it!

Photo: The Aft Driving Position of the 1990s UT722 Far Fosna. The controls for the rudders, the forward azimuthing thruster and the forward and aft tunnel thrusters are on the starboard console. On the port console are the main propulsion controls. In the window the joystick with an associated DP1 system.