15m of anchor chain but how much rope on the Thames

[rubblequeen]

Hi (and I have searched all the posts on this topic) planning to go from Brentford to Oxford on the Thames.

I have 15 m of chain attached to the anchor (there when I bought the boat) but how much rope should I attach while doing that part of the tidal Thames?

Should it be 18mm thick?

 

Thanks

[Naughty Cal]

15m of chain will allow you to anchor in about 5m of water.

 

So to answer your question you need to know how deep the river is.

[GUMPY]

I am at present on the non tidal Thames sitting at anchor with 15m rope and no chain, there is not enough flow to even get the rope tight and I'm having to use a mudweight to keep the stern in.

However if going below Teddington its 10m chain and 30m rope as a minimum.

[ditchcrawler]

I am at present on the non tidal Thames sitting at anchor with 15m rope and no chain, there is not enough flow to even get the rope tight and I'm having to use a mudweight to keep the stern in.

However if going below Teddington its 10m chain and 30m rope as a minimum.

Sounds similar to here on the Gt Ouse. I would need about 10 ft of rope and the weeds are not even bending. It will be short of water soon.

[rubblequeen]

Thanks for the info and have gone for 50m anchor rope add that to my 15 chain and the Sin in Law hanging onto it so should be OK I hope unless someone tells me different.

[Scholar Gypsy]

That will be more than enough - if anything a bit too long, especially if you have an engine failure close to a bridge....

[lockedout]

That will be more than enough - if anything a bit too long, especially if you have an engine failure close to a bridge....

 

Errrrr... you don't have to use all of it!

 

Get a bunch of the small multi coloured zip ties that B&Q sell for a quid and mark your anchor warp and chain at 10m and 5m intervals - then just pay out as much as you need, in this way you should avoid bridges.

 

You can never make a short rope longer (and it is not a good idea to tie lengths together).

[Scholar Gypsy]

That's true, but I wouldn't like to try paying out rope by hand when travelling at 6 knots over the ground: just chuck the anchor over the side and get out of the way ...

[lockedout]

That's true, but I wouldn't like to try paying out rope by hand when travelling at 6 knots over the ground: just chuck the anchor over the side and get out of the way ...

 

If you have your warp and chain marked you can make it off at the required length before you drop the hook and watch your carefully flaked warp disappear into the wet stuff in confidence.

[ditchcrawler]

That's true, but I wouldn't like to try paying out rope by hand when travelling at 6 knots over the ground: just chuck the anchor over the side and get out of the way ...

I wouldn't be out on the water if it was travelling at 6kts

[Scholar Gypsy]

Me neither - but it's quite common to be doing 6 or 7 knots over the ground: 4 kts through the water plus 2-3 kts tide.

 

I wouldn't be out on the water if it was travelling at 6kts

[howardang]

Me neither - but it's quite common to be doing 6 or 7 knots over the ground: 4 kts through the water plus 2-3 kts tide.

 

The bad scenario is 6-7 knots current, which is when the average narrow boat should be tucked up in bed. Also quite common on some rivers.

 

Howard

[parrotguy]

deploy anchor 'dont throw' let out chain and rode then set anchor by having boat pull on it till it holds vessel. Other wise you might just drag anchor and end up shallow on on hill then you will have big problem if you drifted during high tide and water recedes while your sleeping

[Scholar Gypsy]

deploy anchor 'dont throw' let out chain and rode then set anchor by having boat pull on it till it holds vessel. Other wise you might just drag anchor and end up shallow on on hill then you will have big problem if you drifted during high tide and water recedes while your sleeping

 

I think we are confusing two scenarios here:

 

* a controlled stop, where you would turn into the tide/current, bring the boat to a stop, lower the anchor, and then back away in the way you describe. Most narrow boats would struggle to do that (or to moor to the bank safely) in a 7 knot current - see earlier posts

 

* a sudden engine failure while you are doing 7 knots over the ground going though Cannon St railway bridge (which is not unusual). Unless there is another boat very close to you who can get a line to you, you have to chuck the anchor over the side, keep all limbs out of the way, and brace for a rather sudden stop....

Edited July 12, 2013 by Scholar Gypsy

[howardang]

I think we are confusing two scenarios here:

 

* a controlled stop, where you would turn into the tide/current, bring the boat to a stop, lower the anchor, and then back away in the way you describe. Most narrow boats would struggle to do that (or to moor to the bank safely) in a 7 knot current - see earlier posts

 

* a sudden engine failure while you are doing 7 knots over the ground going though Cannon St railway bridge (which is not unusual). Unless there is another boat very close to you who can get a line to you, you have to chuck the anchor over the side, keep all limbs out of the way, and brace for a rather sudden stop....

......and hope that whatever your anchor rope/chain is secured to hold under the sudden heavy load!

An alternative., if circumstances allow - I.e. no weirs etc ahead- which gives you a degree of control is to lower the anchor until it is touching the river bed, then take a turn. The drag of the anchor slows the speed over the ground so that there is a flow of water over the rudder which then gives you a chance to sheer the boat towards safety, or at worse gives you more thinking time.

 

Howard

[larryjc]

 

Errrrr... you don't have to use all of it!

 

Get a bunch of the small multi coloured zip ties that B&Q sell for a quid and mark your anchor warp and chain at 10m and 5m intervals - then just pay out as much as you need, in this way you should avoid bridges.

 

You can never make a short rope longer (and it is not a good idea to tie lengths together).

 

You really need to know the depth of water if you are going to measure out anchor cable - do other people have depth gauges on their boats??. In an emergency on the Thames (And I've just done Limehouse to Teddington) you are going to have make a guess. I've actually got the admiralty charts of the Thames and the depth varies from 10 metres outside Limehouse to less than 2 upriver. Then you need the tidal information to work out the height of tide above the charted depth. As I was looking at this as an emergency system, I worked out the worst case and allowed for that. This meant that for most of the river I would be putting out too much cable but without knowing the actual depth at any point it seemed the safest solution.

However as I was belting through various bridges at 7 knots over the ground I asked myself what I would do if the motor coughed and two things sprang to mind. The first was that even if I did chuck out the anchor it looked likely I would still clobber something and secondly there were an awful lot of boats about and maybe a distress call on the VHF and frantic waving to them might be a better approach.

Edited July 12, 2013 by larryjc

[bizzard]

Unless you have a Hawse pipe, perhaps a wench and all chain and on your anchor I wouldn't just chuck the anchor over, probably not even in an emergency unless your absolutely certain that its rope is perfectly coiled and your sure it will run out properly without snagging on something on the way which is likely to be you and will make a powerful attempt to take you down with it to Davy Jones or just remain snagged and dangling uselessly somewhere just below the water.

It always pays to stay calm and deploy your anchor by lowering it hand over hand which can be done quicker than you think. When the anchor hits bottom you will feel it happen then start paying out more until the anchor grasps the bottom as your boat takes up the slack, keep paying out until you can see a nice angled lay as the boat settles too it and adjusts itself to the prevailing tide, current and wind direction.. Keep a check for any drag and adjust accordingly.

I wouldn't use the plastic zip ties as depth markers on my anchor rope, they have nasty sharp edges to their buckle bits and tang and could lacerate your hands horribly, best to poke in bits of coloured cloth through the rope lay.

Edited July 12, 2013 by bizzard

[rubblequeen]

Thanks all very interesting and Bizzard I don't have a Hawse Pipe or a wench - but if anyone has a spare wench I would be happy for her to come along as my wife wont do this bit of the Thames.

In the mean time I have learnt a lot here thanks.

[Keeping Up]

Another thing you can do, if you are uncertain about your fixings (because you don't want them to be ripped off) is to shackle the end of the rope to one fixing, then use another fixing as well; eg an eye for the end, and then give the rope a couple of turns on the T-stud after that. If there is a sudden stop it may well rip the T-stud off the boat but that will have slowed the boat and absorbed most of the energy, this gives the eye a better chance of holding, and a new T-stud is a small price to pay compared to the value of the boat.

 

When are you making the journey?

[rubblequeen]

Another thing you can do, if you are uncertain about your fixings (because you don't want them to be ripped off) is to shackle the end of the rope to one fixing, then use another fixing as well; eg an eye for the end, and then give the rope a couple of turns on the T-stud after that. If there is a sudden stop it may well rip the T-stud off the boat but that will have slowed the boat and absorbed most of the energy, this gives the eye a better chance of holding, and a new T-stud is a small price to pay compared to the value of the boat.

 

When are you making the journey?

Hoping to enter the Thames on 26 July but not sure about my crew (Sin in Law) if he can't make it then not too sure when I can head out. Might look at hiring someone I beleive has advertised himself on here.

[RichardN]

Hoping to enter the Thames on 26 July but not sure about my crew (Sin in Law) if he can't make it then not too sure when I can head out. Might look at hiring someone I beleive has advertised himself on here.

 

If you are going from Brentford to Teddington don't get over worried, you will have an enjoyable journey providing you have prepared properly, read the guides eg at Thamescruising.co.uk and stpancrascc.co.uk. Loddon has give you good advice about length of rope, most of the advice is good above is good even the contradictory bits. The debate about anchors is always interesting, I have my plan but just hope I never have to use it but that is the only way I will really know what the right answer is, if there is one!

 

If you are going between Limehouse and Brentford then your preparation needs to be really good - I moor in Limehouse, some of the boats going out or coming in scare me as they seem to have no idea. For a first time I would suggest going in convoy - have a look when the St Pancras Cruising Club are going out and join them eg I think there are 17 boats going out tomorrow, I know 9 went down to the barrier today. Very social, very pleasant, very informing, very safe.

 

Go boating and enjoy.

[rubblequeen]

Thanks a lot will be going out from Brentford and I think that I have covered everything. It was mainly the length of rope to the anchor I wasn't sure about. Having read all of the above I feel good now about what to expect and that we will be safe even if the engine does decide to stop. Shouldn't do as had it overhauled and the clutch renewed.

But not experienced enough yet to feel totally confident, which is probably a good thing.

 

My wife's waiting until Teddington to join me!!

[Doodlebug]

Just reaffirming whats already been said - I was in email contact with the port of london and they recommended about 40m of rope to cover from the thames barrier upwards. So I got 50m.

 

Tie it onto something very strong, its been known for the mooring pin to shear off.

 

Hope that helps

 

Doodlebug

[blackrose]

I wouldn't be out on the water if it was travelling at 6kts

 

That will limit your travel on tidal rivers.

The bad scenario is 6-7 knots current, which is when the average narrow boat should be tucked up in bed. Also quite common on some rivers.

 

Howard

 

Yes, but I don't se the problem if you're travelling with the current. I've been down the Thames on a fast ebb tide and still managed to turn into Limehouse - and my boat is meant to be underpowered.

 

If you are going from Brentford to Teddington don't get over worried, you will have an enjoyable journey providing you have prepared properly, read the guides eg at Thamescruising.co.uk and stpancrascc.co.uk. Loddon has give you good advice about length of rope, most of the advice is good above is good even the contradictory bits. The debate about anchors is always interesting, I have my plan but just hope I never have to use it but that is the only way I will really know what the right answer is, if there is one!

 

If you are going between Limehouse and Brentford then your preparation needs to be really good - I moor in Limehouse, some of the boats going out or coming in scare me as they seem to have no idea. For a first time I would suggest going in convoy - have a look when the St Pancras Cruising Club are going out and join them eg I think there are 17 boats going out tomorrow, I know 9 went down to the barrier today. Very social, very pleasant, very informing, very safe.

 

Go boating and enjoy.

 

Limehouse to Brentford is easy, but as you say, preparation is the key. It's Brentford to Limehouse that's the scary one.

 

This is the best bit of prep for the trip:

 

http://www.waterscape.com/media/documents/35.pdf

 

There's an upstream edition too, but I can't seem to find it.

Thanks a lot will be going out from Brentford and I think that I have covered everything. It was mainly the length of rope to the anchor I wasn't sure about. Having read all of the above I feel good now about what to expect and that we will be safe even if the engine does decide to stop. Shouldn't do as had it overhauled and the clutch renewed.

But not experienced enough yet to feel totally confident, which is probably a good thing.

 

My wife's waiting until Teddington to join me!!

 

Brentford to Tedders is fine, nothing to worry about as long as you prepare.

[RichardN]

This is the best bit of prep for the trip:

 

http://www.waterscape.com/media/documents/35.pdf

 

There's an upstream edition too, but I can't seem to find it.

 

 

Links to all the guides are here. Absolutely the best prep that you can do, get a print out.

 

I think I prefer the downstream journey but that could be as we have done the journey several times at Sunset. There is no better way to see Central London then on the helm of your own boat.