Tempory Supplies to Canal Boats.

[Graysonlad]

I own a canal boat. Most canal boats have an on board facility to connect to a shore based supply of 240 volts AC. I never use my connection as I seem never to be at at a mooring where such supplies are available, I am also concerned about the galvanic effects on boats.
In discussing the subject of temporary supplies to a boat I am told that most regs. concern either building/construction sites, domestic or caravan sites but not a temporary supply to a boat. I have probably looked in the wrong places but that does seem to be the case?
From my observations; a boater would run a 13amp domestic extension cable to a standard 13 amp socket somewhere on the canal bank , a house or a club. The socket on the extension reel is then used to connect to the boat via the correct leisure type plug and socket.
Note: Such a connection would be used for couple of days and then the boat sails on.

Question 1: Should there be an electrical incident/accident at whose door would the responsibility rest?
Question 2: At the shore end of the supply chain, what should be in place as a minimum safety requirement before connecting the boat to a supply?
Question 3: In this situation, ignoring for the moment load and volt drop characteristics, is there a maximum length of connection lead, boat to supply, that can be used?

 

[Adam W]

From my observations; a boater would run a 13amp domestic extension cable to a standard 13 amp socket somewhere on the canal bank , a house or a club. The socket on the extension reel is then used to connect to the boat via the correct leisure type plug and socket.
Note: Such a connection would be used for couple of days and then the boat sails on.

Really!? Is that what people do on canals?
I would have thought it would be far safer to use a 'power post' type connection such as used on marinas or caravan sites - firstly there would be less of a trip hazard from a long trailing cable, secondly the cable would be protected along the majority of the length, and thirdly it would be an indication that the supply has the correct characteristics for use on a boat (voltage, rcd protection, supply type etc).

Section 709 of the regs would be a good place to look for guidance.

 

[grantr37]

RCD Protected Pillar with Dual integrated (Individually RCD protected Blue 220V 32 Amp industrial Round Sockets) these are very popular in fact they have them all along the canal here.....
They have a light built into them that illuminates the pier/jetty/canalside next to them, 2 sockets and 2 RCD units with switches for them, in addition they have a switch and RCD for the Light and padlock covers for the sockets...
They have a facility to add an earth Rod beside them which is buried in addition to the CPC that comes with the armoured supply cable and the earth core.
You could bury a 3 core Supply Armoured cable in the purple coloured drainage duct that you get in Builders merchants (bury 15 inches or so with a warning label tape rolled out over it) and I would say the distance would depend on the supply, if it is RCD protected at the supply (original source) end then 25 Meters is reasonable.
Some of these posts have the facility to have a compact digital usage meter fitted inside them which is read via the LCD display or via an IR (InfraRed) contact reader...
For shore outlet to Boat, use Arctic Grade Blue 32 Amp cable terminating in a Dual RCD board inside, use 10 Amps for the sockets and 6 Amps for any lights...
You should use heatshrink on the first 8 inches or so of both ends of this supply to boat lead and also manufacture some kind of bracket or clips to prevent it from sagging and lying submerged in the water, as well as having some "give" in it to allow for movement of the boat...
Fit a 32A Rotary breaker(the yellow and red twist on-off ones) inside the boat between the supply cable and the RCD box(this has a padlock facility for safety lock off), and also I hope you fit a smoke Alarm inside the boat and check the dates on your safety gear and fire extinguisher while you are at it...


As for Galvanics, the boat is not really connected to the earth or using the metalwork for an earth or return path as is used in some DC systems, as this would not be safe or functional for mains from shore, so that should not be an issue....

 

[Graysonlad]

Yes I agree a power post is the best way to connect a boat to a shore supply. Indeed this is what is the norm in a commercial marina.
But I am describing an informal set up, one might describe it as a friend helping a friend out i.e. "run your lead into my shed and plug in". Such sockets are usually just a 13 amp surface socket type without RCD protection.
I think what I am looking for is a definitive statement indicating that the use of an external extension lead supplying power externally, should be via a suitable socket outlet having RCD protection. In other words something that I can show to counter the argument: "What the ......... are you talking about, we have been doing this for years and nothing has ever gone wrong"!!

 

[Graysonlad]

Thank you for the detailed information.
Could I direct you to my quick reply to another member in case you can add to this matter

 

[bugsy]

From my observations; a boater would run a 13amp domestic extension cable to a standard 13 amp socket somewhere on the canal bank , a house or a club. The socket on the extension reel is then used to connect to the boat via the correct leisure type plug and socket.
Ive never seen this! health and safety implications go on forever

 

[Adam W]

Generally speaking, electricians aren't too keen on "informal setups", partly because our job is to install "formal setups"; the same things can (and in fact are more likely to) go wrong with an "informal setup" eg getting electrocuted.

IMO it's not a case of 'just quickly and informally plugging a lead into a friend's shed', you're supplying a boat with mains electricity the same as in a marina and as such should comply with the same regulations as if it were a marina eg supply type must not be TNCS, connectors should be of a suitable type, must be rcd protected etc. Also anodes should be suitably maintained.

It hasn't been mentioned but i assume your shore power connection goes through an isolating transformer?

 

[bugsy]

It hasn't been mentioned but i assume your shore power connection goes through an isolating transformer?

Next post - what's that?

 

[Adam W]

What's what? An isolating transformer or a shore power connection?
Or something else?

 

[Graysonlad]

In my experience canal boats do not make use of isolation transformers. Their installation/use probable follows on from a hull survey being carried out when it is discovered that the steel plates around the waterline have been eroded away due to the galvanic effect. Boats are also fitted with sacrificial anodes which over time also erode away. That is why in 7 years, with our current boat, I have never connected to a shore supply.
Informal arrangements are to be found in all walks of life but I accept that they are never as dangerous as when it involves electricity and spending money. As I said previously, I am trying to combat the argument " nothing has gone wrong before why should it go wrong now?" I am also trying not to lose too many friends.

 

[Spoon]

Not wanting to sound negative (but it will come across that I am), but the problem is that you are asking us advice on something we would never do. We have regulations that we follow. If we don't then we can be in deep trouble. If I has walking along a canal and saw your setup I would tell my family to stay away from it. Also as bugsy has mentioned, you have to think of the health and safety implications of doing this. When I take my kids to some bouncy castles event you will see that the mains cables to the motors are all covered and protected, and that is what is needed just for a day event. From a legal position I cant say, but I can guarantee that if there is an accident someone will be getting sued. If a death is caused the maybe prison for someone. We have heard the argument " nothing has gone wrong before why should it go wrong now? " sooooo many times, and as you know electricity can be dangerous stuff. If someone got hurt the phrase "nothing has gone wrong before why should it go wrong now?" will not comfort them! I think that you probably know its dangerous as you are asking the question. As the saying goes 'If the little voice says, "I wonder if this is safe to do?", it probably isn't.........' . Sorry I could not be more helpful.

 

[telectrix]

i would be inclined not to swim in the canal when the extension lead has been dropped overboard.

 

[Adam W]

I'm no expert but i have done a bit of work on boats including fitting sacrificial anodes; the hulls were made of fibreglass which obviously doesn't conduct electricity but ALL the metal skin fittings, rudders etc were bonded back to anodes, the idea being they erode first leaving everything else intact. The shore power would be supplied via an isolating transformer, presumably for safety (like a shaver socket) and I would imagine to remove the need for traditional earthing - it could be that there appears to be nothing wrong with YOUR boat but for all you know you could be playing havoc with the anodes of any nearby craft (incidentally the US coastguard are already VERY hot on this).
Like I said there are specific requirements in the 17th edition for earthing supplies to marine craft, and no exceptions are made for informal agreements between friends.

I found this article which might be of use to you.

 

[Graysonlad]

I agree about the danger and the fact that we become blind to the consequences.
Our boat and most canal boats are steel built and bonding to the hull takes place without any specific action being needed.
Boaters deal with electricity supplies in different ways, not all I fear with safety in mind. I deal with it by not connecting to a shore supply as our electrical needs are few and can be supplied by our lead acid battery banks. But with the full range domestic appliances being fitted to boats (home from home boating) boats become power hungry and make full use of shore based supply whenever and however available.

 

[grantr37]

I give up with this....."in the USA they do it this way" this is not the USA.