Oarlocks - why U not O?

beermatt's picture
Submitted by beermatt on Thu, 04/10/2014 - 22:03

Forums:

Hi all

By U/O I mean shape. Small inflatables always seem to have Os, but any rigid boats always seem to have Us, and I don' t know why.

I guess the simple answer is that you can get them in and out easily, but it's very little inconvenience to thread through an O from the outside (especially as you can turn the lock parallel with the gunwale), yet it is a massive inconvenience when they "pop out" of a U at the wrong time!

Better still would be U oarlocks with clamps across the top that you can unlock to drop the oars in then lock them in place. But they're even more scarce than Os!

I don't understand why they're so difficult to get hold of. The few I've been able to find aren't suitable (too small, won't fit the gunwale mounting, etc). Haven't come across any galvanised

I know good technique means your oars will generally stay put, but when it's rough and the boat and oars are being knocked around by the waves it's much more difficult to keep them in place. Or simply if you're not concentrating and focusing on something else, for example navigating a tricky part of the harbour or getting back to the beach through the surf. They're the times when you're least focused on your technique, and the time you most need them to stay put!

Anyone shed any light or suggestions?

(You might've guess I'm currently looking for replacements. My previous Nylon oarlocks pretty poor - flexing under any serious power. The mounting eventually pulled its screws out of the gunwale, it was an inconvenience but at least it's given me the incentive to replace them with something better. Won't be sad to see the back of em!)

Cheers

Matt

muckle moose's picture

muckle moose

Sat, 04/12/2014 - 01:33

Hi Matt,
Yes it sounds very familiar! When I first bought my Mirror it had some plastic 'crutches' with some very light aluminum oars which would bend and jump out the crutches when you tried to pull with any force. They we're next to useless! I found some stainless 'U' bolts at work and with some scrap stainless pipe I made some enclosed oarlocks which are really solid. My friend also gave me some old wooden oars which we're full of woodworm. I cleaned them up and threw some glass tape and epoxy at them for strength and durability, which has made rowing the dinghy much more enjoyable. My oars are too short for a really good pull, and I do plan to scarf in an extra bit of length into them soon, but I would like to strengthen the area around the oarlock first, as the hull and gunwhale tend to flex when i put too much pressure on the oar and I don't think the area would put up with much stress with any serious pulling.
If you can imagine the stainless pipe 200mm long, with 2 holes drilled through it the same width as the 'U' bolt and the U-bolt pushed through the 2 holes on the pipe and bolted, then you get the 'P' shaped oarlock. This sits in the nylon 'holt allen' fitting on the Gunwhale.
It also doubles up as a handy handhold for my 3 year old to stop him sliding off the buoyancy tank when heeling over as his feet don't touch the cockpit sole yet!

Euan

PuffinInTegel's picture

PuffinInTegel

Sat, 04/12/2014 - 13:07

When we bought Puffin, there were no oarlocks included and the only pair I could find in Stoke-on-Trent was a pair of galavanized ones which are fully lifeboat-sized. I've been on the lookout for a pair of metal (preferably brass) ones ever since, without wanting brand-new expensive items. The only time I had a bit of a problem with the oars jumping out was when I was ferrying Daniel to the trimaran in a bit of a chop:
Ferryman
because he wouldn't sit still! Generally speaking I am so content with the oarlocks that I still haven't replaced them. At about 6:11 minutes into www.youtube.com/watch?v=ITt8cvMxXEY there is a brief shot of me rowing in the rain.
I'd roughed out those oars for a rubber dinghy before I bought the Mirror and they really are too short, as you can see. Holding them so steeply increases the chance of them jumping out. If anyone wants to replicate them (but I suggest adding at least 30 cm), the drawing is at :http://mirrordiscussforum.org/pictures/gernots/oars.pdf .
Greetings from Berlin,

Gernot H.

sail_and_oar's picture

sail_and_oar

Sun, 04/13/2014 - 00:20

After making loads of mistakes over hundreds (thousands probably) of miles and doing a bit of experimenting and development along the way I use the following setup;

7'10" foot pine oars with plastic oar collars set so the bearing surface is 71" from the oar tip

3/8" (that's the shaft diameter) galvanised rowlocks set in the original places on the gunwales

A home made sculling rowlock offset to starboard fitted into a socket on the transom. The rowlock is lined with rubber and holds the oar shaft fairly snugly to reduce lost motion.

The galvanised rowlocks available locally have some scope for adjustment by squeezing them up in a vice or tapping wit a big soft faced hammer. I adjust them so the oar cannot jump out of the oar collar but so they will pass over the oar shaft. In use they gradually open and need bending back each year or so. I havn't broken one yet on the Mirror but broke a 1/2 inch one on the Wayfarer.

If at all possible I keep sail up when rowing. If I row under sail I use one oar set the same side as the boom and steer with the other hand on the tiller extension. The sails will make some contribution even in a near calm and when the wind returns there is just one oar to put away.

I include the following link about cruising dinghies which contains some of my opinions about rowing
http://www.solentsoundings.org/files/Setting_up_the_Cruising_Dinghy_by_C...

Cliff

beermatt's picture

beermatt

Mon, 04/14/2014 - 11:46

The "P" oarlocks sound very interesting, I think I understand what you mean but not sure if I'm picturing it right. Do you have any photos?

I'm guessing the nylon mounting is simiair to my old ones - where the oarlock (or U bolt in your case) goes through the plastic fitting offset to the side of the gunwale and not into the gunwale itself. The fitting is then fixed to the gunwale just using screws. Mine ripped the screws out of the gunwale under pressure, and if I've got it right might explain why you're also worried about that area. I'd imagine a cavity built into the gunwale itself (sometimes with a metal plate on the top to reinforce it) for the oarlock to drop straight into would be stronger than a screwed in bracket. But I'm no expert, someone more experienced might tell me otherwise!

Interesting that Cliff and Gernot are both getting on OK with the "U"s. Galvanised ones do seem much better than nylon, the flex in the nylon encourages them to jump out under power. Bending them to size sounds useful, but I don't have a vice (or workshop with room to attach one!) or anything else I can think of suitable.... other than maybe wacking them with a hammer! Doesn't the bending backwards and forwards over the years weaken them?

I found that feathering your blades slightly so that they pull the oars slightly downwards during the stroke makes a big difference. As I say though the times you least need them to pop out is usually the times your least focussed on your technique. I'd still feel much more confident with Os (or Us with clamp) and don't understand why they're so scarce. It's not so much why as why not - I don't see any real disadvantages of Os (getting them in and out seems only a minor inconvenience).

Here's a U with clamp example http://www.ebay.co.uk/itm/Oarlocks-Attwood-Oarlocks-Pin-Type-2-Pack-9140... I tried them once, they're quite small and won't fit my full size oars in :-/ but work nicely with my smaller ones. Strangely the pins that hold it in at the top don't have anything to lock the pin in place so they just slide out! :-S No idea what that's all about. It's like a D shackle without the thread!

Yes I've considered a transom rowlock for sculling, would be very handy! Will hopefully get onto that at some point in future. Good description in your cruising guide! I can actually scull the Mirror without the lock - just standing up and using one hand as a pivot point, it's a great hassle free way of covering a few yards but puts quite a twisting strain on your back without a lock on the transom. Wouldn't a mounting point get in the way of the rudder tho? I imagined ideally having one that fits into the same bracket as the rudder mounting so you could just pop the rudder off and replace with your scull-lock. No driling holes or additional brackets in the transom that way!

PuffinInTegel's picture

PuffinInTegel

Mon, 04/14/2014 - 14:08

Hi Matt,
Cliff's solution with sleeves that cannot lift out ouf the open-top rowlocks is the optimum. I recently realized that it's definitely easier going alongside if you can simply lift the dockside oar out of the oarlock quickly.
Of course you might say that one could pull "O" type rowlocks out with the oars, but then you've got to fix them in place on the oar with a lanyard or similar to prevent rattling down the shaft and rapping you on the knuckles. I do not advocate pinning oars as this weakens them at the crucial point (I broke an oar that was pinned in a rented boat once - fell over backwards and bruised my head as a result) and prevents you feathering them if you're going against the wind.
Greetings to all readers and lurkers!
Gernot H.

P.S. edit : I too have found it possible to scull short distances without an additional rowlock and, with a bit of practice and the centreboard down, you can also paddle Indian-canoe style while sitting in the stern (it's just important to push the oar/paddle at an angle to keep the boat going straight). The latter solution is inelegant when single-handed because the bow is up in the air that way.

sail_and_oar's picture

sail_and_oar

Mon, 04/14/2014 - 16:38

I've found a few u tube clips which may illustrate some of the options

First Sarah and I in Wayfarer. The oars Sarah is using are the one's I use for the Mirror. There are two sets of oar collars to accomodate boats of different beam. The sculling oar is home made and has an 18 degree crank near the blade - much better than a straight oar. There's an elastic downhaul fixed to the handle end of the oar which helps with fatigue

https://www.youtube.com/watch?v=iprvlZm6mSk

My friend Chris Waite with his Rosie Mae (currently up for sail, a heavy 10 foot centreboarder with a lugsail, ashore in West Sussex UK). I'd been toying with this idea myself and I'm grateful to Chris for saving me all the trouble of the development work.

https://www.youtube.com/watch?v=QudODfZhxII

And the "proper" way

https://www.youtube.com/watch?v=w4qpNsrtWzM

More ways than one to skin a cat

Cliff

PuffinInTegel's picture

PuffinInTegel

Tue, 04/15/2014 - 12:12

Have you got a sketch of the mechanism from Chris? This could be my solution for longer stretches on the canals where sailing is prohibited and traffic discourages you from sitting with your back facing forward.
Gernot H.

David Cooper

Tue, 04/15/2014 - 20:17

I heard that long ago there was a race between two rowing boats of the kind used in the Olympics, one powered by four rowers and the other powered by four cyclists with the power sent to a propeller. The cyclists won easily. I've been wondering for a long time if it would be possible to fit such a system to a Mirror and whether it would be better than rowing.

62816inBerlin's picture

62816inBerlin

Tue, 04/15/2014 - 22:56

See the second video linked by Cliff.
Not a propeller, but quite as effective!

sail_and_oar's picture

sail_and_oar

Tue, 04/15/2014 - 23:49

Chris and a few of my other friends who build their own boats put their ideas in their website.

http://uk-hbbr-forum.967333.n3.nabble.com/

From what they seem to say as soon as you go anywhere near a boat with a drill and some glue you automatically become a member.

The unregulated nature of boats (in the UK at least) means that there's a lot of scope for the home inventor. Some of these guys are really imaginative and some of their creations are impressive.

Chris has a very long running topic/discussion about his home designed 12 foot cruising dinghy "Polly Wee" and I think there are photos of the yuloh assembly. I did a 90 mile cruise in company with Chris a few years ago. I took the Mirror and he took an extremely heavy 15 foot cabin boat which sets 200 sq feet of sail. On all points of sail and most wind speeds the boats were unfeasibly closely matched, perhaps the Mirror had the edge. A four day race and a memorable trip. Chris is a great guy and a fine sailor.

There have been all sorts of schemes for front facing rowing, rear view mirrors, pedal power, Hobie drive etc for waters like the canals. They all seem to have problems in some way or other and we return (yet again) to the rowing oars or double paddle in the case of the kayak and similar easily driven boats. Most of the innovative propulsion ideas seem to put a lot of stress into the hull which will need reinforcing and you end up losing track of the fact that what you started off with was a beautifully balenced sailing boat.

Anybody looking to optimise rowing performance would do well to visit the Hannu's boatyard website.

http://koti.kapsi.fi/hvartial/

Cliff

David Cooper

Wed, 04/16/2014 - 21:49

I've looked through the relevant threads on that forum and found that half of one of my ideas already exists: http://www.amazon.co.uk/JARVIS-WATERSNAKE-SALTWATER-ELECTRIC-OUTBOARD/dp... - this is the least powerful model available and may (or may not) be the most suitable for that reason. If you use this on the back of a small boat, you could then power it via a dynamo worked by pushing strings forwards with leg power as you sit with the dynamo behind you. This would minimise the cost and the amount of junk you have to add to the boat (i.e. no cranks, chain and chainrings). There would be more power lost along the way than with a mechanical drive, but there would be no need for a hole in the bottom of the boat for a propeller shaft to go through and the weight at the back could be kept to a minimum. You would not need a battery for this to work, but you might need to add some electronics to avoid putting too much power in from the dynamo. The big question is though, would it be more efficient than rowing? If so, then it could be the way to go.

The key advantage of using this system of propulsion is that you could then combine it with solar panels and a battery under the thwart (where its weight is best located) to provide a more versatile system, minimising the amount of work you have to put in. A more powerful motor such as the http://www.amazon.co.uk/Minn-Kota-Riptide-Saltwater-Outboard/dp/B002T3QP... might be more suited to this, and one of the reviewers does talk about using it with a solar panel:-

"While repairing my gas outboard I purchased a Riptide 45 to propel a Boston Whaler 11 tender around the anchorage. I also purchased an Instapark 50 watt solar panel to charge a 32 amp AGM battery on board the Whaler so essentially its a solar powered skiff and it works great. The setup is so good I don't want to put the gas motor back on. The Riptide 45 on the highest setting uses a bit less than one Amp per minute and makes my Whaler go probably five knots or so, sort of the same speed and power a 10 HP outboard would give at just above idle. My first test was a water run carrying thirty five gallons out to the boat, no problem. Then one day while going down the channel I encountered a stranded 21 foot Whaler with two kids and four desperate adults on board. They had two gas motors, a main and a kicker and both were dead. I told them I didn't think I could help them because I only had a little electric motor. The wind was blowing and clouds were spraying mist as I hooked up a tow line anyway and surprisingly was able to get them all the way back to their slip. The tow was slow but sure and amazed us all. "

You could run a motor of this kind and row at the same time, and use the sails, to fight against currents which would normally defeat you, and all of this done in a quiet, civilised way without having to carry a tank of explosives.

beermatt's picture

beermatt

Wed, 04/16/2014 - 23:39

Some interesting ideas, I'll look forward to browsing through some of the designs on Cliff's links. I've mulled over propulsion methods a lot, keeps my mind entertained when I can't sleep lol!

Glad to hear someone else had a rear view mirror idea. I was going to mention it in response to Gernot's canal post actually. Wouldn't it be possbile to pick up some old car wing mirrors (ebay or something) and make a mounting point on the gunwale? I'm creative like that..... although rarely succesfully!

Rowing allows you to put so much more power in than using a paddle (either 2 ppl or kayak style), but it's difficult to make a row boat the same weight, slipstream, and seaworthiness of a kayak. And of course the issue of looking backwards. Rear view mirrors might help from a functional point of view, but it's not the same experience as taking in the scenery etc facing forwards.

Theoretically legs are stronger than upper body so pedal power should be even more productive than rowing.... yet you rarely see it. Touristy style pedaloes are horrible big heavy things - they're ok as a gimmick for ppl to hire for a bit of fun.... but an insult to hydrodynamics lol! Would be interesting to see how effective a performance oriented pedal drive could be.

And if you have absolutely no shame whatsoever there's always this!... :-P
https://www.youtube.com/watch?v=g9bmLv6iUj4
https://www.youtube.com/watch?v=b_5eMMkIOeo

(Sorry for the digression.)

I'm not a big fan of electric power because batteries are a pain. David's battery-less dynamo + outboard sounds pretty ingenous tho! Max output might be an issue, but that outboard is still tempting at just £70!

David Cooper

Thu, 04/17/2014 - 18:41

The high price of some of the electric motors suggests that in salt water there may be good reason for spending all the extra money, so that's something that needs to be checked carefully before parting with any cash - the £70 one may be best suited to doing a bit of fishing on a lake. I'm also not sure how easy it is to handle batteries in a capsize in salt water - a short circuit could be very nasty. Ideally you'd want them stored inside buoyancy tanks, but you'd also need sealed connections to the motor, though they surely must have thought of all that. As for the battery type, some of the lithium batteries used to power electric cars could be worth investigating as they'd provide massively more range for the same weight and make a more powerful motor worth having for trying to get up rapids and narrow sections of rivers. I know that one electric car has 40 batteries powering it, so they ought to be possible to use individually - it isn't just a solid half-ton block of battery. I expect it would cost a couple of thousand pounds for the ideal set up, though you'd probably also need to replace the batteries every five years or so.

PuffinInTegel's picture

PuffinInTegel

Thu, 04/17/2014 - 12:16

On holiday in San Francisco (before cycling over the Golden Gate bridge) in 2007 we met a cyclist who had a tiny rear-view mirror attached to his helmet or sunglasses (not sure which it was). I've thought of buying one of those as I cycle in town occasionally anyway. If they attach to the helmet, I'll have to find a way of fixing them to my sailing hat!
Cheers,
Gernot

P.S. edited in case someone thinks I'm still in SF.

beermatt's picture

beermatt

Sat, 04/19/2014 - 22:45

Ha yeh as a kid I had some rear view sunglasses where the outer 3rd of the lense was mirrored. Great gimmick we thought they were really cool, can't remember how effective they were tho lol.

Yeh I'm not keen on electric cars. Batteries are a pain in consumer electronics, I can't imagine them in anything high powered. Most rechargeables appear to have a lifespan of about 3-4 years and are affected by all sorts - hot, cold, impact, dis/recharge cycles,etc, and damage everything in their vicinity if they leak! Replacing 40 :-O batteries in your car every few years can't be economical or good for the environment. If it's not human-powered I'd rather just take my little Suzuki DF2.5 out :-D

If you ever get chance to implement the dynamo version I'd be interested to see it!

Going back to Gernot's Indian Style Paddling mention a while ago, I've tried one-sided paddling before and no matter how I twist it or turn it always spins round lol. Just done some youtubeing to see how it should be done and will give it another go next time. Seems there's various methods https://www.youtube.com/watch?v=JpthPymQmis . I imagine until your technique is 100% you could cheat by leaving the rudder on and lashed slightly to one side.

Back to the original question, I'm still not completely covinced by the U but seems regular galvanised is a good enough solution. One issue of vicing them down to size is if you have different diameter oars. I have 2 sets - an old solid pair with collars that are beautiful to row with, and my modern lightweight pine jointed oars that don't pull as well but are easier to stow when I'm out sailing. Both significantly different diameters! Not the biggest problem in the world, just another advantage of closed locks over open.

Anyway I've ordered some galvanised+plates online - intending to drill straight into the block on the gunwale then re-inforce it, rather than screwed in like the last ones. This'll be interesting! (I'm a bit of a novice at these kind of modifications.)

Lin

Sat, 07/12/2014 - 20:21

I'm in the very luck position of owing two mirrors at the moment, a ply and a grp. The woody has two mounting points for rowlocks and oars to match. I refurb'd the oars over the winter (actually I gave them to my wife, as she wanted to 'help'.........) Many sheets of sandpaper later - most only partially worn, I had a pair of sticks! Only kidding, she did a great job and they came up very nice with a couple of coats of lacquer.

The major problem then arose the first time we used them, when testing the integrity of the refurbished hull.Tthe oars seemed to exert a rather heavy force on the row lock mount on the gunwhale, and despite the previous owners attemtps to relieve the situation they seemed ready to pop off at any minute!

I've just picked up my grp boat today and its missing one row lock mount - the previous owner suggested that as the dinghy was used by a club and never rowed, it was more likely a clumsy cadet probably trod on it and ripped it out - ho hum! Do I replace it or simply carry a canoe paddle instead, along with the Seagull outboard lol????

On the face of it, I don't think I like the idea of rowing a mirror, its all to easy to damage the hull, esp if you have to put your back into it in a fast tide like we have here on the Exe.

Regards Lin.

PuffinInTegel's picture

PuffinInTegel

Sun, 07/13/2014 - 19:25

I've even fitted a second set of mounts on my boat and I had to row into a force 4/5 with just the jib up to get out on the lake earlier this year. The gunwales of a wooden boat are strong enough and it should be possible to fit oarlock fittings to a GRP boat with a bit of frozen-snot experience!
Cheers, Gernot H.

TTS's picture

TTS

Mon, 07/14/2014 - 00:44

The gunwales of a Mirror do flex a bit when rowing, but they hold just fine.
I did row my Mirror and found it rowing very well.

beermatt's picture

beermatt

Sat, 07/19/2014 - 15:18

Gernot and TTS must've been lucky to have good mountings. I've heard many stories of problems with Mirror oarlocks, and have personally pulled the mountings out of all 3 boats that I've owned (2 x plywood, 1 x GRP). I must not know my own strength! (Although when you miss-time crossing an estuary with a 3 knot tide and find yourself downstream of the mooring you were trying to get to you can surprise yourself!)

I recently finished my oarlock replacement project. It doesn't look that elegant but was designed to be strong enough to hopefully buck the trend of failures. Block of hardwood epoxied into the hollow GRP gunwale, reinforced with 4 stainless 8mm flanged bolts (+ large washers); galvanised plate on top, held down by 2 stainless 4mm x 40mm wood screws.

Let's hope this one isn't just another stastistic!

www.imgur.com/a/1RpRM#UyvRQRT

PuffinInTegel's picture

PuffinInTegel

Sat, 07/19/2014 - 01:12

I tried using your URLs and putting them in the img tag, and then I am unable to save my reply.
Is there some kind of blockage on your picture server site?
Cheers,
Gernot H.

beermatt's picture

beermatt

Sat, 07/19/2014 - 15:25

No blocks, Imgur is a popular image sharing site (a bit more focused on ad-hoc/public/annonymous sharing than Picasa, Skydrive, FB, Flickr, etc). It's the same problem I had a while ago posted in the technical thread: Whenever I put http:// on the beginning of something it won't post and asks me to save a file locally.

Putting www. without the http:// at the beginning works.

The Imgur URL doesn't strictly use www but I've just tried and and seems to accept it :)

TTS's picture

TTS

Sat, 07/19/2014 - 01:57

Nice solution, Beermatt.

62816inBerlin's picture

62816inBerlin

Sun, 07/20/2014 - 13:31

here's a copy of the pictures, now saved on a local (forum) directory. The problem seems to occur with source URLs that use the secure http protocol and scripts to show the pictures as I was unable to paste pictures from facebook, too. The simple http links to pictures on imgur didn't work either - I extracted them from the source code and downloaded the pictures to my computer, then uploaded them to our forum site, and that works, as you can see.
Matt's oarlock mount

Matt's oarlock mount-1

When I enter the address of the same picture stored at imgur, I get a message saying :
>>>>OK
The server is temporarily unable to service your request due to maintenance downtime or capacity problems. Please try again later. <<<<<

Cheers, Gernot H.

P.S. I just tried entering the imgur URL instead of just writing "imgur", and then the same strange behaviour occurred: I could preview my comment but couldn't save it. Then I removed the URL and I was able to save my comment, as you can see.

curlew's picture

curlew

Sun, 07/20/2014 - 22:43

The advantage of the U-type of oarlock is that you can lift the oar out if a collision is going to happen!
My oars have a winding of thin rope around them over about 20 cm to prevent wear, and at the top of this is a Turk's Head to stop them slipping down. I often sail and row, sometimes facing forwards, sometimes just one oar, depending on conditions.
I am in the middle of making a spray hood - the frame is finished and now starting the sowing.
David