I am planning on entering the local raft race which is held every year in aid of the RNLI. It is quite competitive with teams made up of lifeboat volunteers, coastguard, firefighters, local businesses and private entries. I myself have participated in the race twice through work without much success, but this year I would like to build a raft and field a competitive crew myself.

The regulations state that any materials used should not originally have started out with marine use in mind. Fixings and adhesives are not allowed to be used to hold the raft together, lashing being the only method allowed. Asides from these rules it is pretty much free reign in terms of boat/crew size and design.

I was originally thinking of using big blue plastic barrels for buoyancy but I can’t find any cheap enough locally, about £15 each seems the going rate locally. So over to you knowledgeable bods of STW, any ideas for alternative hull materials? Any advice on design?

Tick

Inner tubes for the hull. Big ones.

Rafting was a standard CCF / Army Cadets  / Scouts type activity when I was of that age.

It might be worth speaking to your local Scout group to see if you can borrow some equipment for a donation to their fund.

Or,  do you have any fancy private schools nearby who have their own lake and a CCF?

i Would probably be looking for old bathtubs to use as floats (don’t forget to bung the plug hole)

but I can’t find any cheap enough locally, about £15 each seems the going rate locally

try calling a local few food manufacturing places – things like blue barrels and IBCs that their ingredients arrive in are quite expensive to clean back to food safe and / or ship back empty so  you might not have to pay much / anything to take them off their hands. I’ve picked a few IBCs from a meat processing plant cheap (having previously contained bright blue food colouring and smelling of aniseed…mmmmm qualitymeat products) a farming friend gets his IBCs free from a little posh deli that imports balsamic vinegar.

Inner tubes for the hull. Big ones.

Check in advance they’re air tight. As a teenager me and some friends hiked up a pass somewhere in the lakes – I forget where – with a bunch of tractor inner tubes and a foot pump. We then spent far longer than anticipated pumping them up before wading into the river back to discover it was shockingly, searingly painfully cold. Jumped back out – contemplated walking back with wet shoes / clothes. Then decided it wouldn’t be painful once we were numb so jumped back in and floated down stream. My inner tube was leaking so compared to my pals i was slowing floating lower and lower in the water and pretty much entirely numb from the neck down with the cold. Arrived back at the camp site and went to the showers to warm up. As the feeling returned I discovered I’d dragged my sensation-less arse over every sharp rock for about 2 miles and was cut, bruised and grazed to ribbons and mush.

Sounds a hoot, how many has the raft got to hold?

go to the local scrap yard and cut the top off a transit jobs a good un 🙂

I was once part of a very unsuccessful raft race crew. Our “raft” consisted of 4 x 45 gallon drums 2 either side welded together with some cross section steel. I can thoroughly recommend you avoid this design at all costs. At the ripe age of 17 I had what is still possibly one of the worst days of my life. It was as streamlined as an oil tanker going sideways and had a top speed of possibly 1mph even with 6 fit venture scouts on board. We were out there for nearly 3 hrs, had it boarded and stolen by some adults who we got gobby with who then towed it in to the middle of the river and cut it loose whilst we had a piss, we came dead last and were assisted by being towed in by two lads in a canoe to complete our utter shame in front of about 200 folk!

Never again!

Thanks for the replies everyone, some good ideas and some good stories!

No limit to size of crew (within reason I guess)

Google matlock bath raft race. It’s run every year on boxing day (not the one we did or I think we would have all died) there’s some pretty fancy entries that go in that. Might give you a few picture ideas?

A slightly left field suggestion. The film industry gets through huge quantities of polystyrene for set building. Theres branches of ‘Scenery Salvage’ in Manchester and Bucks – they’re basically a scrapyard for sets – maybe see if any big polycarved bits of scenery have come their way – float down the river on a mayan temple.

Build yourself a wooden structure and ‘tank’ it with a big tarp. Saw that at a local raft race the other day and thought it was a good idea – they did theirs like the General Lee.

Traditional way was oil drums welded together to make a cylinder + outrigger. Remarkably fast, no use of adhesives but may fall foul of lashing only rule.

Wooden framed canoe with DPC wrapping it could be good – see link

A good source of large sheets of tough waterproof fabric is the companies that print/install billboard ads. Look at the billboards in your locale- rather than pasted up in individual paper sheets these are now printed on large single sheets of tough vinyl – the company that manages the billboards will have their company name on there somewhere (clear channel, JC Deceau etc) – give them a call and ask if you can go through their skips.

polystyrene insulation makes good floatation  100+ kilos a sheet

Next door neighbour is a Baker in a large factory. He gets tomatoes delivered in huge drums and then they go to the scrap after. You might have to weld the top back on but it’s cheaper than £15 a barrel.

Get googling your local factories. You might even get a sponsor while your at it?

A raft you say, and you want to win?

OK

Don’t build it on top of big blue 200 litre  (gallon?) drums unless your team is extremely fat, as you’ll float way too high out the water.  You’ll shag your back leaning all the way down to get a power stroke.

Don’t use oil drums as it’ll be two heavy.

We used about 30 small plastic drums (40 litres?) in a catamaran styley.  We ensured that we left the bits between front pair and rear pair (of crew) relatively free of cross members.  Which meant we could switch hands and paddle inboard as well as normal, which is brilliant as otherwise one arm does nearly all the work.  Also allowed our 6ft 6″ Scotland 2nd row forward to match his strokes with his opposite number by paddling inboard occasionaly.  All the forward thrust with less turning moment (is that a thing?)

Anyway, we won the 1990 Lock Lomond Raft race.  Happy days

Lots of very good ideas thanks chaps, skin on frame construction might be the ticket and I’m thinking of substituting timber for 32mm plastic waste pipe zip tied together, might flex horrendously though.

I’m thinking of substituting timber for 32mm plastic waste pipe zip tied together,]

I’d think again about that

Lock Lomond Raft race

**** bastatd  piece of shit Samsung phone

Apologies for not keeping this thread updated, we managed to build a raft out of inflatable fitness balls of all things! It was super stable and very light. The race was the Sunday before last (5th Aug) and we came in 5th place out of 20 rafts. A very enjoyable day all round.

Here is the raft…

[url=https://flic.kr/p/MVxFD7]Raft Race 2018[/url] by Kieran20492, on Flickr

And an obligatory action shot…

[url=https://flic.kr/p/MVxFEj]Raft Race 2018[/url] by Kieran20492, on Flickr

nice idea, nostrils! comfy to kneel on and even more of a core workout, double bonus.  I shall remember this, thank you.

I guess you could lash some semi rigid plastic sheet between the midpoints of front and back balls for extra hydrodynamism.

Thanks Ned, they worked out surprisingly cheap too! You are right, the raft could do with some sort of bow to prevent it digging into the water. Out of the top 5 we were the only raft with 4 paddlers, all the rest had 6 or 8. Would have benefited from the extra horsepower I reckon!

Using that blue plastic rope to lash things together? Soak it in a bucket of water overnight – it tends to loosen a bit when it gets wet so best to have that happen *before* you use it 😉

rachel

Fantastic – I like the safety knee pads! Disappointed there were no helmets 😃

I would like to build a raft and float it down the Ribble, which is the most canoe hostile river in England, just to annoy the huntin’ shootin’ fishin’ fraternity. I wonder if I would make it alive to Preston?

We used about 30 small plastic drums (40 litres?) in a catamaran styley

This is good advice.

Have done a fair bit of raft building, and found that the only design that worked reliably was a Catamaran.  Love the  core ball idea!  Also:

Don’t underestimate the barrel’s desire to wiggle free – they have to be really secure or will work their way loose.  Once you lose one, the rest of the raft will deconstruct itself fairly quickly

Key thing to remember is that any wood frame in the water is useful buoyancy, any above the water is just weight.

We sell a lot of our product in 25 kg steel drums, which get recycled for all kinds of things in the export markets. The most creative use I have seen is as a big air duct with the ends cut out and welded end to end. They would make excellent pontoons lashed to a frame end to end. New ones cost £12.50 each though so you’d have to go with used. I guess you’d need around ten to displace enough water to carry two people.

Using that blue plastic rope to lash things together? Soak it in a bucket of water overnight – it tends to loosen a bit when it gets wet so best to have that happen *before* you use it

Don’t worry, the raft was well tested beforehand and unsurprisingly the rope did require a lot of re-tensioning after being dunked in the sea.

Fantastic – I like the safety knee pads! Disappointed there were no helmets

The knee pads weren’t for safety, purely for comfort, that ply deck is torture to kneel on for 10+ minutes of paddling.

I would like to build a raft and float it down the Ribble, which is the most canoe hostile river in England, just to annoy the huntin’ shootin’ fishin’ fraternity. I wonder if I would make it alive to Preston?

I hear the sound of banjo’s….

(I am game for a wind up…)

As a member of the aforementioned “huntin’ shootin’ fishin’ fraternity” (near Gisburn) go for it! Sounds like great banter!

Big blue barrels will catch the wind like a bastard. My main memories of a raft race when younger was fruitlessly battling a mild side wind. Keep it as low as possible.

Place I used to work at had isopropanol for the print machines delivered in 25 litre containers, which I reckon would be ideal, lashed end-on in a couple of rows, catamaran-stylee, I think they’re used in all sorts of industries, I also used to get plate developer delivered in the same size containers, they’d be used to send waste chemistry away for recycling and treatment. I’d guess it’s possible to find businesses with those size containers going cheap.

I do like the use of the exercise balls, that’s genius!

how about some lengths of the largest bore drainage pipe with end caps (and duct tape) to make dummy logs? Should have a better cross section than barrels.

STW raft race?

Just a mention on the physics of floating.

You will get 1kg of floatation for each 1ltr of volume. So, of the big barrels (Oil Drum size) that are typically about 200ltrs each, each will keep afloat 200kgs of people and structure.  Once they get more than half submerged they begin to sink more for each kg you add, if they are on the side.

Ideally match the number of barrels and weight of raft/people so that the barrels are half submerged.  Gives you the ideal ratio of volume in the water (drag) to reserve bouyancy in case of the water getting choppy. So one barrel on it’s side supports about 100kg and will sink to about its midline.

This sounds counterintuitive as well, but the wider the raft, ie people sat further apart laterally, the easier it is to keep in a straight line, you can get more turning force from each paddle, and the more stable it will be.  More stability makes vigourous paddling easier.

How many are you hoping to muster for you team?

Well, its getting towards that time of year so I thought I’d resurrect this thread.

Raft race course this year is at slack tide with strong headwinds a possibility, going to spend the next month designing and building a new raft with this in mind.

Any other STW bods done/doing any raft racing this year?

Let the scrounging of materials commence!

Started building the raft today, barrels with ply deck, held together with rope and cable ties, shes a big ‘un!