Powerboating - Part Fourteen

I am sitting on the afterdeck of my boat, watching the sun sink into the horizon at the end of a warm Queensland day. Hacksaw, my faithful cattle dog, is snoring contentedly on the cabin house. The beer and bone hour has just about ended, and with the boat gently rocking at anchor, it's time to think about getting a meal together, possibly watching the cricket on the box and turning in for a good night's sleep.

Here we get to the point of this month's article: a good night's sleep on a boat at anchor is largely dependent on the anchor and all that goes with it. There is nothing worse than a dark night, a rising wind and a vessel that starts to drag its anchor. This situation raises fear in the stoutest breast, confusion in the most coldly practical mind and hours of nagging terror. I know, it's happened to me a few times over the years!

So let's talk about this lump of iron that we often chuck over the bow without a second thought. Firstly, anchors come in a variety of styles and most of us have our favourites. Personally, I swear by the plough design over all others, but I know a lot of boating people would disagree. I'm not here to say one is better than the other. If your chosen anchor works for you, stick with it.

THE PLOUGH ANCHOR
The plough anchor is made by a range of manufacturers and, as the name suggests, looks like a farmer's plough. When it hits the bottom of the sea bed and the boat starts to pull on the shank, the toe of the anchor begins to plough into the bottom. It's assisted in this by lead cast into the area just behind the toe. If the bottom is good for anchoring (and we'll talk more on this later), the anchor generally buries itself after being dragged a couple of shank lengths and stays put - the boat not being able to generate enough force to pull it through the bottom any further.

Plough anchors are generally extremely heavy, with the top-quality ones having the shank made from forged steel. In cheaper versions, the shank is simply cut out of heavy steel plate, and while this method of manufacture is adequate, it's never going to be as strong as drop forging. (With anchors, as with pretty much everything else in life, you get what you pay for.)

The shank is joined to the body by a hinge arrangement that allows some sideways pull on the shank without upsetting the anchor.

Plough-style anchors stow well in bow anchor rollers but can be a toe-stubbing menace when lashed to the deck. They hold well in mud and sand, but if the mud is deep, they can have a problem getting a decent bite. When retrieved they bring up a fair amount of the bottom with them.

The angle the shank makes to the body of the plough is important - I can vouch for this. Years ago a cheap imitation of the famous CQR plough appeared on the market, and as usual, being short of funds, I bought one of the damned things. I dragged in almost every anchorage between Sydney and the Whitsundays before I finally came to my senses and got rid of it.

Be wary, buy the best and buy the right size, which is the next thing to consider when discussing plough anchors.

The old saying "a pound of anchor for every foot of boat" is a pretty good starting point. A 35lb plough on a 32ft boat is a pretty good combination. I'm conservative, however, and although my boat is 32ft, I have a 45lb plough hanging in the rollers, with a 35lb anchor lashed to the deck for emergencies. I know this is overkill, but I like to sleep well at anchor. God knows, I've had some miserable sleeps at times, and I've never noticed anyone selling heavy anchors when you're hanging on a lee shore in a stiff breeze and all you've got on the bottom is a cheap bit of engineering rubbish.

So if you intend to do a bit of cruising and the plough is your anchor of choice, you won't do any harm by going a few pounds over the recommended size.

THE BRUCE ANCHOR
Another popular style of anchor is the Bruce. This looks similar to the plough, but the shank is fixed to the body and it doesn't have any added weight (lead) in its construction.

The genuine article is cast steel, which has been heat-treated to eliminate stress build-up in the metal. There are no welds to fail and, more importantly, no hinge to wear as in the plough.

My experience with this type is limited - I've already stated my preference - but people who use them swear they are superior in every way.

Once again, the weight of the anchor must be matched to the boat. As with all plough styles in mud, they are a burden to clean after retrieval.

The Bruce anchor is a reasonably common sight on boats these days, which seems to be a good indication of their performance. They hang well in the rollers but are an even bigger headache than the plough to store on deck.

THE ADMIRALTY ANCHOR
Still occasionally seen these days is the old Admiralty pattern. This is the anchor that looks like an anchor, rather than something more at home on the farm. Its shape decorates everything from trendy nautical-themed bars to the badges on those appalling yachting caps and blazers. In my opinion that's about all it is good for, but I know many will disagree.

The rod at the end of the shank is displaced 90° to the flukes, which helps it dig in. I must admit, it digs in through coarse grassed bottoms better than almost any other style, but its holding power in sand and mud is limited. If it snags in rocks, you can pretty well kiss it goodbye. (Mine is on the bottom at Port Stephens, but that's another story.)

One thing it does really well is take great chunks out of the bow as it is retrieved. It's also an absolute bugger of a thing to stow in the rollers.

THE DANFORTH ANCHOR
The last anchor design we are going to look at in detail is the Danforth pattern. This anchor digs in quickly and is particularly good in sand - better, in my experience, than the plough.

However, its design is not as robust, and if it wedges in rock on the bottom, it can become damaged on a hard retrieval, especially with the modern electric winches available.

Danforth anchors' light weight in relation to their holding power is probably their most attractive feature. Typically, a 20lb Danforth can hold a boat up to 35ft.

They can be a bit prone to snagging in the rollers unless the rollers have been specially designed for them. However, they stow well on the deck. For some reason they are a lot easier to clean than plough styles if they have been used in mud.

I have a 20-pounder sitting in the lazarette. It has a 5m chain trace (more on this later) and 50m of rope, and I have used it over sand with good results. I wouldn't cruise with just a Danforth, but I'm happy to lug one around and use it from time to time.

OTHER OPTIONS
This is by no means an exhaustive treatise on the different anchors on the market today. In fact it seems that a new development or design is introduced every year. You makes your choice and you pays your money. Mushroom anchors, river anchors, grapnels and reef picks all have their good and bad points.

A lot depends on the area where you are boating. Anchoring over a coral reef with a 40lb plough and 100m of chain out does environmental damage that would make you weep if you could see it, so a selection of anchors to suit the occasion is not only necessary but mandatory if we want to keep what we have left. Think about it.

ROPE OR CHAIN?
There's not much point having a wonderful anchor if you haven't got anything with which to connect it to the boat. For this we need rope or chain. What's the best?

Weight for weight, rope is a lot stronger than chain and has the added advantage of having a certain amount of stretch, which provides elasticity when the boat jerks on the anchor. This factor makes for a much more comfortable anchorage in swell than a chain.

The disadvantage of rope is that it can be easily damaged by chafe, particularly on coral bottoms, and it won't self-stow as well as a chain. To recover a rope anchor it must either be pulled up hand over hand manually, and if that's your cup of tea then good luck to you, or it must be brought aboard using a winch.

Modern anchor winches have a combined rope/chain gypsy and this means that they can grip the rope with sufficient friction to pull the anchor back aboard. If this is your preferred method, never attach the rope directly to the anchor. A length of chain, called a 'trace' and generally between 5-10m, should first be connected to the anchor's 'D' ring using a good quality shackle, preferably galvanised rather than stainless steel. Stainless shackles used in this situation have an alarming susceptibility to stress failure.

The shackle should be 'moused'; that is, a piece of galvanised or stainless wire is passed through the shackle pin's eye, around the shackle's body and then twisted tight. This prevents the pin from undoing when on the bottom, which, believe me, is not uncommon.

The rope should be spliced into the end of the chain in the neatest possible fashion, as this allows the winch to make a smooth transition from the rope to the chain. This assembly is called the 'anchor rode'.

This system can be made to work quite well, but it is tough on the rope, particularly where it is spliced into the chain. Therefore it is important that it is inspected regularly.

If the rope comes up with a lot of mud, slippage can occur at the gypsy, which can be a nuisance. But, generally, by far the biggest headache is the anchor locker's design. If your boat has a locker that is deep and roomy, then there is seldom a problem, as the rope has plenty of room to lie naturally in the locker.

However, if the anchor locker appears to be an afterthought on the boatbuilder's part, and sadly this is often the case, then the rope tends to bunch up as it is fed into the locker by the winch. The next time the anchor is released a complicated tangle can develop, which requires much swearing to undo.

If your anchor locker is to blame, then I don't think there is any solution but to go to an all-chain system (more on that in a minute).

When anchoring with a rope/chain arrangement, lower the anchor to the bottom and then go gently astern, allowing the rope to feed out of the locker of its own accord. This prevents the rope from bunching up like a big bundle of knitting on the bottom and possibly fouling the anchor's flukes.

The ratio of rope length to water depth is called the 'scope', and a minimum scope of five-to-one is the norm. This means that in a depth of 5m it would be necessary to have 25m of rope played out over the bow. A scope of seven-to-one would be better if the anchorage is exposed to a bit of weather. When all the scope is payed out, put the engine astern and dig the anchor in. Watch as the strain comes on the line and holds the boat in its position. If it doesn't, then start all over again until it does.

ALL CHAIN
The most popular method of anchoring is to use all chain. It's easier to handle, thanks to the modern electric anchor windlass, and a far safer system all round.

Firstly, it doesn't require a person on the foredeck, as all retrieval and anchoring can be done remotely from the helmstation. This means that the helm is constantly monitored during this critical phase. Secondly, the sheer weight of the chain plays an important part in keeping the boat in one place.

To explain further, imagine a boat with 50m of 10mm chain between it and the anchor, and assume that this 50m of chain weighs around 100kg, which in fact it does. As the boat moves backward, before it can apply any pressure on the anchor, it must first lift this mass of chain off the sea bottom and then pull it taut. To do this requires considerable force, and unless the weather is starting to get really mongrel and push hard on the boat, this force won't be generated.

The anchoring technique most commonly employed with chain is to select the desired location and lower the anchor to the bottom slowly. Don't allow the anchor chain to rush out over the bow-roller like an escaping bilge rat, as it will end up in a big pile on the bottom that will probably foul the anchor.

The scope for chain anchoring is less than for rope: three-to-one for good anchorages and five-to-one when the weather is against you. For really bad conditions, let it all out - it's not going to help you if it's sitting in the locker.

By the way, always have the anchor chain's end shackled to the boat in some manner in the locker. It's expensive and embarrassing to watch the whole lot disappear over the side because this was neglected!

As in rope anchoring, go astern and dig the anchor in. If it won't hold you when you are going astern at moderate revs, it won't hold in a blow, and you won't sleep if you're worrying about it.

The size of chain is measured by the diameter of the links. For boats up to around 30ft, 8mm is fine, for 30-45ft boats, 10mm is fine. Over that, then 13mm is recommended.

As for the length of chain, I think 50m would be the absolute minimum. I have 100m but there have been times when I wished I'd had a thousand. Generally, the locker's size and the amount of weight in the bow area play a big part in this decision - 100m of 10mm chain weighs over 200kg and takes up a lot of room.

So, here we are back where this article started, snugly at anchor and aiming to get a good night's sleep. You will if you have done your homework and equipped your boat with good ground tackle.

Next month we'll look at anchor winches and associated equipment.