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Topsail Tattler

Boat Handling Under Engine – Part 3: “Let’s turn this ship around!”

by | Feb 14, 2020 | Archived News (Live), Skills School

In the last article we looked at ways to get our boats heading backwards without offering too much entertainment to the harbour-side gawkers. However, the vast majority of us are going to feel far happier when we’ve got our little ships heading the “right” way once more. This time, as our series on close quarters boat handling under engine continues, the Skipper tackles turning around.

On the face of it an about-face sounds easy, a simple matter of putting the rudder hard over and keeping it there until the bow is pointing towards our target. The surprise for most folks graduating to traditional boats from their more modern fin-keeled offspring comes in the form of quite how much space this can require. Weighing in at 24 tons, with a plumb stem and full forefoot, Amelie Rose needs a channel width of at least 3.5 boat lengths (50+ metres) in order to execute a turn in this way – even in favourable conditions. That kind of swinging room is not always on hand, so here are a few ways that we’ve learned to reduce the turning circle to something a little more realistic.

Technique 1: Tightening a simple turn
Let us first consider a few salient points:

  • A boat’s momentum will incline her to resist any turn and to try instead to continue on her previous track. A quick check on Wikipedia confirms that this momentum is a product of her mass and her velocity.
  • Even a traditional long keel doesn’t have a perfect grip on the water in the way that a car’s tyres do on a dry road, so her momentum will cause her to “skid” sideways through the water.
  • Even if she were to grip the water perfectly; increasing her forward velocity in a simple turn will increase the size of the turn as she will always be travelling forwards as well as turning. The faster she is moving the more ground she’ll cover before completing the turn.
  • As we are intending to travel forwards during the turn we have the option of using prop-wash to assist (see our first boat handling article). The benefits gained by this will be most apparent at slower speeds.
  • Travelling too slowly through the water will cause the rudder and keel to “stall” – resulting in a loss of steerage. If we’re trying to turn into a stiff breeze then the wind pressure on the bow will exacerbate this effect.

It follows therefore that the tightest possible turn will be conducted at or near minimum steerage speed for the prevalent conditions, with the assistance of prop-wash.

Examples of performing a "simple" turn

The outcomes of a simple turn to starboard. 1) Leaving the engine in tick-over forwards with the rudder hard over the turn takes nearly 3 ½ boat lengths to complete. 2) Putting the engine in neutral as we commence the turn and then re-engaging tick-over at the apex shaves half a boat length from the turning circle. 3) Engine in neutral to the apex then pulses of forward throttle to keep steerage and help to complete the turn, this trims a whole boat length from the space required.

Putting it all together – a simple turn
On Amelie Rose – we’ll generally start a “simple” turn by popping the throttle into neutral from tick-over forwards, then pushing the tiller hard to port or starboard.

By the time she reaches the apex of the turn, drag from the rudder and resistance from the water will normally reduce her speed to just above minimum steerage.

We then use “pulses” of forward power to utilise prop-wash to keep steerage way and to help complete the turn without unnecessary and unhelpful acceleration.

If we are turning to windward we may find that we need to start the pulses of power earlier in order to maintain steerage. Conversely when turning away from the breeze we may allow the boat to stall out for a short while, aiding a sharper turn as the bow is blown away from the wind.

Practice makes perfect:
Practicing this manoeuvre is pretty simple – especially if you have a nice wide fairway with minimal traffic somewhere to hand. First, try a fully powered turn, leaving the engine in tick-over throughout. Once you’ve established how much room you need for this you can try tightening the turn using the techniques discussed above. Having a few goes will help you to zero in on your minimum steerage speed and should also show you the effect of the wind as you circle back and forth.

Technique 2: You spin me right round
Done well this technique looks like an elephant performing ballet and will result in folks asking you questions about where you fitted the bow thrusters and why it is that yours don’t make that annoying whining noise. Essentially the aim is to use the effects of prop kick and prop wash to drag the stern of the vessel around her pivot point with the minimum of collateral movement (or damage) fore or aft. This is such a useful technique that on Amelie Rose there is a standing joke that “she doesn’t turn to port” in that we would always rather head to the port side of a narrow channel and spin her to starboard rather than try to turn her against her prop-kick.

Before you start be sure to check what the tide is up to. Remember that you are going to spin the boat around on her axis, and so during much of the manoeuvre you will not be able to negate any tidal effects. You will therefore be drifting towards wherever the tide is headed (one notable time in Amelie Rose’s history this was at a knot and a half towards a closing bridge). It’s also worth knowing that wind pressure on the bow will impede (or even stop) your progress if you are turning into it but that it will help the bow through the turn if you are heading away from it.

In describing this I’m going to assume that your prop kicks to port (as most seem to) but if you have a starboard kicker then you’ll need to reverse port and starboard to make it work.

Putting it all together – spinning the boat
Begin the process by putting the helm over for a hard starboard turn where it should remain for the entire event. It’s tempting to reverse it as you reverse the engine but this is completely unnecessary as the aim is that at no point will the boat actually be travelling forwards or backwards and so the only time the rudder is doing anything is when we’re firing wash over it from the propeller.

Now fire pulses of wash back at the rudder with the throttle in forward gear. The rudder will deflect these pushing the stern sideways. As you are using the prop in the way that it was designed (i.e. for forwards propulsion) the boat will tend to gain forward speed quickly as you do this, hence we only fire pulses as these will maximise the sideways effect for the minimum of forward push. Don’t be afraid of revs here, each pulse should be to 2/3rds or even more of maximum donkey.

As soon as the boat picks up her skirts and begins to move switch to a long hard blast of astern (pausing for a second in neutral to spare your poor little gear box). The long blast of astern will kill her forward way and give you a good hard kick to port. Remember that the prop doesn’t work too well in reverse so this can be a long (not pulsed) blast, and again, don’t be afraid to give it the whole can of beans. The second she starts to move backwards (and if she’s tiller steered you’ll feel that) it’s back to pulses of forwards again.

From here on in it’s a simple case of “rinse and repeat” until you find she’s facing the right way. Using transits on the shore will help you to figure out when she starts to creep forward or back (and also to monitor tidal drift). If you’re able to see the bow from your helm position then you can watch to see how well she’s turning, as well as catch the looks of concern and amazement as you swing your bowsprit past (or for even more kudos, over) the assembled on-lookers.

Spinning the boat - commencing the manouvre

Using prop wash and prop kick to spin the boat around her centre of lateral resistance. Note that the boat will have a tendency to move around unless you are spot on at switching back and forth between forward and reverse before she gets any way on.

Practice makes perfect:
If you learn no other close quarters technique I suggest that you learn this one. Not only learn it, but practice it until you can spin your boat around in spaces that are barely wider than she is long (in fair conditions at least). There’s no need to start off on the most difficult level of this game though. Find a sheltered space with stuff ashore to help you monitor fore and aft motion and give it a go. Once you get the hang of your boat, you’ll probably find that there is a rhythm to the throttle (on Amelie Rose it’s three short blasts of forward to one long blast of aft). You may also want to get the hang of starting the spin whilst still moving forwards – using an extra-long blast of astern to both stop the boat and initiate the turn (especially useful if the wind will assist by blowing the bow off).

Technique 3: Clap on canvas!
As observed back in the first boat handing article, our canvas can also be pushed into service to help us turn the boat when the other methods aren’t working but Mother Nature is being kind with the wind direction.

Remember:

  • The sails won’t be available to you if you’ve got them triced up with the covers on so be sure to have them ready for action if there is any chance that you may require them.
  • If the sails are prepared but the crew aren’t then don’t be too surprised at the result – which will probably involve the use of fenders and a fair quantity of colourful Anglo-Saxon language.
  • If you do hoist some canvas be aware that once it’s role is complete it can become a hazard with alarming speed so be ready to get it down (or rolled away) again rapidly.

The most common use of canvas whilst manoeuvring Amelie Rose under engine is to encourage the bow around a tight corner with the wind either blowing on the nose or from one side or other. We generally use her staysail as it’s easy to get up, easy to back and easy to get down in a hurry. If you have one then even more leverage will be available using a roller-reefing/furling jib, but be sure of your ability to dowse the damned thing quickly. An advantage of hanked-on sails and roller reefing systems (but not roller-furling ones) is that you can reduce the amount of sail that you show to the breeze if things are getting lively.

Using canvas to help us turn

Using the staysail to aid a tight turn counter to the prop-kick. 1) As we approach, slow the boat to minimum steerage speed. 2) As the pivot point approaches the turn push the tiller hard over, hoist and back the staysail. 3) Once the turn is complete get some way on quickly and dowse that canvas!

Putting it all together – using the staysail to help a tight turn
Preparation, clear briefing and good communication are all important when using canvas in a confined space. On Amelie Rose, where we often sail with plenty of crew, we’d normally have a different crewmember briefed, stationed and ready for each possible task. This includes separate hands on both sheets so that we can back the sail or let it draw, one at the halyard to haul it up and let it fall and one at the stemhead to control how much goes aloft and pull it all down sharpish when required. With fewer hands you’ll need to double up the tasks or think about another option.

As you’ll generally using a foresail to encourage the bow to blow off in the direction that you require you’ll benefit by slowing the boat down as you reach the corner that you’re trying to negotiate – giving the wind more time to get to work. If your prop-kick will assist by turning the bow into the corner then consider using reverse to slow her down but otherwise dropping the boat into neutral as you approach should suffice as it’s likely that the wind will be slowing you too.

As the boat’s pivot point approaches the corner, call for the hoist and almost immediately ask the sheet crew to back the sail. Remember, perfect sail shape is not the point here; you’re just increasing the windage at the bow to assist the turn. At the same time steer hard into the corner and use pulses of engine, both to keep steerage and to add prop wash to the party of turning forces.

As you approach your new heading you can call for the drop, pop the engine into gear and tootle away.

Practice makes perfect:
This is another easy one to practice on a wide fairway somewhere with no audience and an hour to spare before the pubs open. Try it first with the wind on the nose and a backed foresail and then with various angles of breeze on the helpful side and even with the breeze initially on slightly the “wrong” side of the bow. Different combinations of timings for the hoist and drop and backed and drawing sails will work best for the different angles and only experience will tell you how your boat will react.

Next time we’ll top up our close quarters toolboxes with a look at ferry-gliding, warping and winding.

1 Comment

  1. Chris Heape

    I think this is brilliant, it will make a great handbook! Love your style of writing, informative and entertaining, it jumps my mind back on board straight away!

    Reply

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