If you’ve never had to do it, here’s how
Towing one boat with another was a regular sight in the past. The lead narrowboat with a thumping diesel motor for propulsion and the silent butty behind. Between them, they would carry many thousands of tons of goods from one place to another. It still happens today but on a much lower scale.
It isn’t this form of towing that we are going to address here. We are talking about towing another boat because of mechanical breakdown or to help a boat off an obstacle. Before you don your shining armour and leap to someone’s aid, there are one or two things you might want to consider.
BEFORE YOU START
This isn’t something that should be done lightly. Boats that tow regularly are set up for it with strong towing points and with butties that have enlarged rudders to help unpowered steering. They are most likely steered by experienced operators too. However, if you need to do it to help a stricken vessel, you are probably going to consider using your normal mooring lines.
Rope has a finite load carrying capacity, the ‘breaking strain’, and all ropes have a value in weight terms after which they might break. The manufacturer’s quoted breaking strain relates to the material used in making the rope, its diameter, its type of makeup, e.g. braid on braid, three-strand etc.
For example, a three-strand, polypropylene rope of 14mm diameter would have a breaking strain of around 2,000kg. However, that is when it breaks and you don’t want that to happen. The figure you really need is the safe working load (SWL), and that could be as low as 173kg for the same rope. The only way you will know for sure is to get the manufacturer’s spec for the rope and perhaps even go as far as having a certificate to prove it.
Now I know what you will be saying: “I have towed another boat with one of my 14mm mooring lines and the boat weighed 15 tonnes.” Yes and that’s because you weren’t lifting the boat in the air but pulling it through the water so the rope doesn’t experience the same load.
Remember, the figures quoted by the rope-maker don’t take account of the age or condition of the rope, and knots or splices in it will also affect the strength.
The point is that you probably don’t know the SWL of your mooring lines and when you pull another boat there is no simple way of quickly calculating the load being put on the rope. This becomes even more unpredictable if you try to ‘snatch’ the towed vessel off an obstruction such as a sandbank.
Snatching is where you start with a slack line and hit the power to get your boat moving at some speed before the line pulls tight. It’s a very dangerous manoeuvre because it puts unpredictable strain on the tow rope and whatever the rope is connected to. Stern dollies and T-studs, for example, are for mooring lines. Even an anchor shouldn’t really be connected to them let alone a 15-tonne
boat being snatched off an obstacle.
The least that is going to happen is that your boat stops suddenly but your body keeps going and you bounce off the cabin. At worst, the rope may snap or the bow T-stud of the towed boat becomes detached from the hull and hits you. Either way, you will really wish you were somewhere else and it might just be the hospital.
If you really must tow then start with a tight line and use a steady pull to get the boat moving slowly, keep as many people as possible away from the tow rope and also keep an eye on your now essential power plant.
EFFECT ON YOUR ENGINE
The horsepower of the engine installed in your boat was selected by the boat builder to power the likely weight of your own boat with you on board and not with another 15 tonnes dragging behind it. It will most likely get the towed boat moving, (even one horse can do that), but keep an eye on the engine temperature while you are doing it. If you aren’t careful, there will be two stricken boats on the water. Don’t just keep an eye on the engine though, also keep an eye on where you are going.
KEEP YOURSELF SAFE
In order for your bow to steer to starboard the stern must go to port, ably assisted by the movement of your rudder. However, if there is a heavy weight trying to pull your stern the other way, you may find your steering is compromised and the bow goes in a place you don’t want it to. Hello bridge hole! And then of course, the towed boat also has to steer.
As stated above, butties have enlarged rudders which are extremely useful to steer an unpowered boat that doesn’t have the benefit of prop wash. Even then, steering a butty successfully takes a bit of practise.
The stricken vessel you are towing might be steered by a relative novice and will almost certainly have a standard rudder and this is nowhere near as good. The towing vessel might get around the corner, but the towed vessel may just get dragged through the undergrowth and potentially cause damage to the bank and the boat.
‘The towing vessel might get around the corner, but the towed vessel may just get dragged through the undergrowth’
For sure, the owner of the boat in distress will be very grateful for the tow but might not be quite as happy when you drag the side of his boat along the side of a bridge hole taking all that brand new paint off. He/she may be so annoyed; he/she may want to make a claim on your insurance. Are you insured to tow another vessel? Are you insured to be towed by an unauthorised recovery boat? You might want to check.
While you are doing your ‘risk assessment’ you might also want to consider what you are going to do to slow down, how you are going to give signals to the towed boat, (and them to you), what will you do when you meet another boat and your plan for other obstacles such as locks, lift/swing bridges and tunnels. The latter will ask you to check if the towed boat has the ability to illuminate a tunnel light.
THE LONG AND SHORT OF IT
Many of the hazards relating to manoeuvring can be helped by the length of rope you use.
Most of the time, a short line is the best and preferable in the form of a proper tow rope. Using two ropes works even better where both are connected to the towed vessel’s bow T-stud and the other ends are connected to each of your stern dollies.
Whatever you use, make sure you can remove the towing line quickly in an emergency. Even a round turn and two half hitches takes a while to undo and might put your hands just where they don’t need to be when you are trying to slow down the other boat.
On wider waterways you might also consider not towing at all but breasting up alongside the stricken vessel.
Not only is it much easier to steer the combination but, providing you tie off at the bow and the stern, you also have ‘brakes’.
A SUMMARY OF DOs AND DON’Ts
Only do it if you really have to and if you do then do it for a short distance. Use the best, thickest rope available. Keep it slow and steady. Ask yourself: what happens if the tow rope snaps? Consider the route you will take and plan ahead, maybe even have a towpath walker to warn others of your approach. Check your insurance. Keep a watch on your own engine.
IT ISN’T AS EASY AS IT LOOKS
Watching experienced boaters operating an historic pair especially through locks is truly wonderful and they make it look easy. But they didn’t get to be that good without having the right kit and also lots and lots of practise.
Think very carefully before taking on the role of rescuer. One casualty can quickly become two and a well-meaning tow can end up in disaster if you don’t know what you are doing.
Best set up, note the ropes cross over
Proper rope for a long tow length
Be wary of long tow ropes
... keep it short
But if you don’t need it long...
Most of the time a short line is best
Proper towing ropes, left and centre
Long ropes can be a hazard
Towing boat steering with a short rope
Shorter is much better