Update on the Test Oars

Toilers in the Oararium, enjoying the delights of spokeshaving

It’s been a good team effort getting the new oars done.This is a short report on our experience.

We decided to go with the longer oars, 4.3 metres at stations 1, 2 and 3 and 4 metres at station 4, i.e. fourteen and thirteen feet, using the same basic construction ideas as our existing oars but making us a long oar club. We decided to stick with flat blades, as we think they’re easier for beginners and suspect that the membership will not support the introduction of spoon blades, whatever the potential gain in efficiency.

The handles are got out from solid Douglas fir, spliced to shafts that have centres of Western Red Cedar with protective strips of Douglas fir on the front and back faces. We think this is advisable given how easy it is to damage the cedar.

Topher provided dimensions for oars that start at 90mm fore and aft by 45mm deep and taper toward the tip, which we then adjusted to allow for the Douglas fir strips, giving the following dimensions, ten stations from the pin to tip, column A being  fore and aft, column B the same corrected and column C the depth.

The shafts were quite tricky to get out, because of the need to be very accurate, especially as one got near the tip. I had to balance my fear of planing off too much with increasing worries that that the results wouldn’t be strong enough, compounded by the fact that the WRC centres looked very skimpy prior to the strips being added.

The next step was applying the strips, which Mr H had kindly machined for us.

So many clamps were needed that this resulted in eight separate gluing sessions.

Once the strips were on they were cleaned up and the edges rounded, then given a good sanding.

Our flat blades are a slimmed down version of what we already have, with a reduced surface area of about 160 square inches against our previous 185 and the length drawn out to 36 inches.

The handles were rounded off and the oars delivered to Ray the Happy Varnisher for his magic.

In the meantime we considered how to go about the oar gates. The aim is to produce a more accurate hold and eliminate the clunking in the present system of a plywood plate. The design produced by Don Currie of New Zealand looked about right, but we decided to limit ourselves to two gears, ratio 3.0:1 and 2.8:1. The white rubbing strips inside are from scrap rigging that had been condemned for insurance purposes and is widely available free from boatyards, duly sawn up.

Here is the prototype for comparison.

Overall I would say that no greater skills were required than for our original oars, just more time and care to ensure that the finer tolerances were kept to and to handle the finer strips. We will call the new oars the Cluthas, as we expect them to bring us to victory on the Clyde in a week’s time.

Still talking about oars!

Above is an image of the recommended hardwood/softwood oar, courtesy of Topher Dawson, complete with the photographer’s shadowy signature.

The oars that we will build are very similar, except that we won’t be having the ball and slot oarlock system devised by Topher, nor his spoon blades.

For that system to work perfectly it’s essential for the pins to be absolutely vertical, something difficult to achieve, given differing crew weights, for example an exceptionally heavy cox brings the skiff down at the stern. Also it’s more difficult to make accurately. Correctly set up, the system works perfectly and smoothly, but we have decided to stick with simplicity.

For those who are interested, here are details of the ball and slot system:

We intend to adopt the pin and gate oarlock system devised by Don Currie, shown here:

Here is Don’s drawing, showing construction details:

You will see from the photograph that Don has made wearing strips from some hardwood. We could use oak, or perhaps source thin strips of polypropylene, which the rules allow. He has provided dowel spacers held by strong woodscrews and the photograph shows plastic bushes round these.

These details are not today’s problem, but will give us something to talk about while getting on with the main work. In the meantime please be thinking about sourcing suitable  polyprop, plastic strips etc that can be recycled for a seagoing future.

We have now sourced sufficient Douglas Fir and Western Red Cedar to make our set of oars.  The first task is to make a cutting schedule, so that the wonderful Mr H in his mountain workshop won’t get annoyed at having his time wasted.

Marking out precisely and very carefully where you are going to cut is far more important that just charging ahead and possibly wasting expensive material. The old adage “measure twice, cut once” applies.

We have more than enough WRC, as I had to buy two pieces – timber yards won’t just cut off the length that you need. We’ve got just enough DF to produce four handles plus strips to go on the front and rear faces of the WRC, to protect the latter from dents and bashes. The strips should be 5mm or probably 6mm thick if we can manage to get that width out of what we have. Each saw cut costs you the width of the blade, about 3mm or 4mm usually, rapidly using up stock.

We will soon run oar building workshops, but for these to be of any benefit it’s important that people understand the problems and help with solutions. As  start please read Topher’s detailed instructions, copied below. We need to modify these somewhat, to take account of the flat blades, and adjust the dimensions to allow for the DF faces on the WRC.  For example I’m inclined to make these faces full length, for strength and ease of building, rather than just the length of the outboard, WRC sections. This means that the handle stock would be machined 78mm x 45mm rather than 90mm x 45mm, allowing for the two 6mm strips.

Here is an image of the handles, per Topher:

 He is suggesting ovoid, 40mm for and aft by 35 deep. I think we should go slightly less depth and also produce a pear-shaped end.

There follow Topher’s Instructions. Please note carefully the suggested dimensions, especially at the outboard end. It makes me think that our current oars are massively over-strength!

Making the Beta test hardwood/softwood oar shaft for the St Ayles oar

The hardwood/softwood shaft has a rectangular cross section with slightly rounded corners for its whole length, tapering down in depth and width towards the tip.

  • The inboard section inside the boat is made of a dense hardwood like oak or ash and the outboard section is made of a light softwood like Western Red Cedar (WRC), spruce or Douglas Fir (Oregon pine). This improves the balance.
  • The number 2 and 3 oars have the thole pin mounted not in the gunwale but in a block screwed and glued to the inside of the gunwale. This moves the pin inboard by about 70mm which allows the oar to be shorter and therefore lighter than current oars. It also allows the bow, 2 and 3 oars to be the same length, 4.3m. The stroke oar is 4.0m. “Short oars” are all 3.5m.
  • The depth and width at each station along the shaft are the same for all lengths of shaft, but the distance between each station varies with the length of the shaft.
  • The spoon blade is a spooned narrow Macon shape made from two blade halves of 4mm plywood. The blade halves are stitched together with cable ties to form a shape which is curved longitudinally and slightly vee shaped in cross section. This is then epoxied and the cable ties removed. The curve allows the light plywood to be stiffer and stronger than a flat blade and more efficient in the water. This light blade contributes to the light balance of the oar.
  • A flat 4mm ply blade can also be made.

Making the hardwood/softwood shaft:

Whatever species of timber is used, it has to be clear of knots and straight grained. In the UK the most likely timbers for the inboard are ash or oak, but elm or beech could also be used. Outside the UK there will be favoured local woods of at least 700kg/m^3 density.

The outboard timber needs to be light, straight grained, clear and available in lengths of 3.5m, although they can be scarphed. Western Red Cedar, spruce, and Douglas Fir all fit this bill. WRC is the lightest, spruce is the most expensive, and Douglas is the heaviest. Slight variations of the width and depth of the tapered outboard are in the design to take account of the different density, strength and stiffness of the three timbers. If you are using other timbers, measure the density and stiffness of a sample of your timber and pick the design for the timber which most resembles yours.

The procedure depends on what dimension of timber you start with. If you use 100×50 thicknessed down to 90×45 then make one 45mm face straight, flat and at right angles to the 90mm face. Use this face for the aft face (nearest to the cox). Mark the stations on it and draw the widths at each station. Cut this taper leaving enough timber to plane to a smooth curve. You may want to use this blank to draw around on the other shafts.

If you are using Western Red Cedar in the commonly available 150×25 sawn finish house cladding plank size, you will need to thickness it to clean up the sawn surfaces and then glue two layers together to make a blank. Your blank will likely be a bit under the 45mm thickness needed near the gunwale, but only short padding pieces 150mm long are needed because it thins rapidly.

Then on the fore and aft faces, mark a centre line and set off the depth equally on both sides of the centreline. You want to take wood off both sides, perhaps with a hand held power planer to begin with, and then a hand plane as you get near the line. Finally you knock off the sharp edges with a hand plane and some sandpaper, aiming for a 5mm radius or whatever seems right. This is to make the oar shaft more robust against knocks, and kinder to rowers.

The oar needs a big scarph joint just outside the gunwale where the hardwood meets the softwood. This is just like the scarphs in the skiff planking but bigger. Make sure the final oar is straight!

It is easiest to make a hardwood blank 90x45x1500 and work the end down to the handle size, make the slot and line it with 3mm plastic, and make the scarph, before gluing it to the outboard.

Dimensions:

This table shows the width (fore and aft) of the shaft at each station, in mm. Station 0 is at the gunwale, and the ten stations are equally spaced going out from the gunwale to the tip of the oar. The cross section of the oar is everywhere rectangular, with  slightly rounded corners, about 5mm radius.

The depth of the shaft (top to bottom) is exactly half of the width at every station.

The inboard part of the oar, from the handle end to the gunwale, is hardwood of a constant 90×45 rectangular section.

 

The dimensions vary a little for different timbers, to take account of the different density, stiffness and strength of each timber. It is important to avoid knots, especially near the forward and aft faces of the shaft.

pastedGraphic.png

 

If making this oar out of Western Red Cedar, the lightest of all three timbers, the shaft can be made of two layers of 150×25 plank which is the most commonly available size, used for house cladding. It needs to be thicknessed down to clean up the surface, but taking off as little wood as possible. Depending on the plank, you may end up with 19-22mm thickness. A small section on each side may be needed to thicken up the 150mm nearest to the gunwale to make 45mm.

The oars come in three lengths. The shortest, 3.5m, is for short oar clubs, and all four oars are 3.5m long.

For long oar clubs the stroke is 4.0m long, and oars 1, 2 and 3 are 4.3m long. To allow oars 2 and 3 to be this short, the pins need to be mounted on blocks glued to the inside of the gunwale.

The dimensions at each station are the same, but the distance between each station is less for the shorter oars.

pastedGraphic.png

The inboard and outboard are joined with a 6:1 scarph, 270mm long. The scarph joint is cut so that the feather end of the outboard is at the top of the oar, and the feather end of the inboard is at the bottom of the oar.

The handle needs to be 400mm long, and around 40mm in diameter according to taste. A good section is oval 35mm deep and 40mm fore and aft, which allows smaller hands to grip but keeps more strength. It is sensible to make a gradual transition to the rectangular section for rowers’ comfort and to reduce stress concentrations.

Varnish or paint the oar well, as the additional weight is less than the weight of moisture soaked up by an inadequate paint job.

Talking about Oars


 

I hope that this post won’t be too technical, but at least it could provide something to talk about if anyone is out on a first date in Anstruther, North Berwick or Ullapool, where oars are the talk of the steamie.

 

At the last AGM the membership of SCRA approved a motion to set up a group of builders and trial rowers with a view to moving towards a standard oar that perhaps might at some distant future date become compulsory for use in racing. Because people are fond of their individual designs and skiffies tend to cherish the slightly anarchic nature of coastal rowing the latter was maybe only a remote possibility.

 

The group recently reported and SCRA has now decided to recognise the general feeling against compulsion, with the result that two choices are now offered to clubs for each of oar length, construction, type of blade and oarlock system. Clubs are now invited to offer to make a new set of oars incorporating these variations and allow members from other clubs to visit and try them out.

 

Our club had already decided to make a new set of oars and been accepted as a “testing” club, so we can now go ahead.

 

Every one of the recommendations would produce a significant improvement in terms of efficiency and comfort over what most clubs have been using.

 

Regarding length, some clubs are sold on short oars and the recommendation would be for these to be 3.5 metres, which happens to be the length of our existing oars.

 

Longer oars would be 4.3 metres, 14 feet 1 ½ inches, which is a bit shorter than what some have been using, but gaining efficiency by positioning the pins on the inboard side of the gunwale by about 70 mm. In this event the stroke oar would be 4 metres, a foot shorter. Avoiding the extreme lengths in excess of fifteen feet, that some clubs have gone for, keeps the oars manageable and reasonably light.

 

Your committee feel that we should go for the longer length.

 

Regarding construction, the choices are an all softwood oar or a mix of softwood outboard and hardwood inboard. The latter is what we already use and produces oars that are better balanced and that would be our choice.

 

Blades can be flat or spooned, in the latter case to a specified design. Spoon blades seem to be more efficient, in that they scoop and hold water better, but this comes at the cost of being a bit more difficult to use, because you have to learn to lift them at the end of each stroke to avoid catching a crab! Because we row so often with relatively inexperienced people it seems better to stick with the flat blades we are used to.

 

Finally, regarding oarlock systems, the choices are between an improved version of what we already use, giving a more positive entry angle to the blade and better control, or an innovative new idea, with the oar slotting over a special pin with a round top. In either case the pin will be made from a tough acetal, rather than oak, greatly reducing friction. Our idea would be to stick with what we are used to and benefit from the acetal pin.

 

The plan is to go ahead with oar workshops as soon as we have acquired the timber needed. The sketch shows the basic design that we will be working to.

 

Isle of Mull Regatta – 6 and 7 September 2014 – Call for Rowers

Selkie and Eala Bhan in Tobermory
At the launching of Eala Bhan earlier this year.

 

The first Isle of Mull Skiff Regatta will take place in September and looks like providing a fantastic weekend of racing and just enjoying the magic of Tobermory. Selkie is duly entered and booked on the Oban to Craignure ferry departing at 11.55 on Friday 5th September, so she’ll be there anyway with a nucleus of rowers. There’s plenty of scope for more of us to take part and it will be great if we can field more than just one crew. 

Our friends on Mull visited our regatta in force and showed us a thing or two, so it will be great to return the favour.

To date Selkie and her people have competed at several events, in Ullapool (twice), Otter Ferry, Loch Vennacher and Loch Insch. Those of us who’ve been have always had a really good time and enjoyed real hospitality and kindness.  If you haven’t tried you really don’t know what you’ve been missing. Please use the booking section of this site to register your interest and allow us to give the Mulleachs some real competition! 

 

 

Toberonochy Open Day

Toberonochy June meeting 2We set off from the Pontoon just after midday and rowed down against tide and wind to Toberonochy, arriving about 1345, where we were greeted by a good percentage of the population and enjoyed cheery chat, burgers and tea.

We were challenged to a race against the two Luing skiffs, a nice triangular course out across the Sound and back, about 1 kilometre. Selkie came in first, followed by the big Shetlander and Hinba third. This could count as Selkie’s first actual win!

Toberonochy racephoto courtesy of Iain Robb

The return trip entailed a brisk row up through Ardinamir against a tide that ran like a little river, followed by a real skoosh out through Cuan and a gentle row behind a nice Southerly breeze. Back on pontoon by 1715 in time for Selkie’s evening excursion.  

Winter job list

Work starts in  John McFarlane’s big new shed at 10.00 am on Sunday 12 January – see Sue’s comment in last post

With Selkie safely inside (see pics of the trip across below) we’ve got two weeks to complete her winter maintenance, so here goes with the start of a job list. The good news is that it’s extremely short, as she’s travelled a lot of sea and road miles with remarkably little damage.

The hull will take a few days to dry out and we’ll start on the outside, which will be ready for the first session on Sunday. 

Please treat the following as a provisional list and feel free to add suggestions by way of comments.

 Outside of hull

Lightly sand the lowest five strakes to give a key. Apply two coats top coat.  

Repair small damaged section where stem has been caught by the trailer. This needs thickened epoxy, which can only be applied once the stem is totally dry, so this area must be kept clear of paint.

The sheerstrake requires touching up where needed. I don’t think it needs a complete coat of paint.

Inside of hull

Remove mast step and stroke footrest fitting. I’ll take these away and coat them with epoxy to stabilise them.

Remove thole pins.

Clean then sand interior, removing any paint runs etc. Apply two coats paint.

Forward Seat

Make and instal a seat to same pattern as the cox seat. We can measure for this and I’ll make a kit of parts for it.

We can source a piece of heavy duty netting to go under the seat as an alternative to a locker for the anchor, flares etc.

Modifications

I’ll do a separate note about shifting the pin positions aft and changing the stroke side to starboard. Most of this to be done off the boat, apart from drilling the gunwales.

Footrests

The existing ones at positions 1, 2 and 3 need adjusting to give intermediate positions, also to make them easier to use. Eventually we can make new ones if we adopt longer oars.

Launching trolley

Add some wood to position the bow in correct position when loaded on.

Road trailer

Adjust forward block so that it engages with the polyprop strip.

Drill number plate supports for pins to give a positive position.

Jan trip to Balvicar 1 Jan trip to Balvicar 2 Jan trip to Balvicar 3

Thoughts on the AGM

Four of us attended the meeting in Callander, not the best thing for the legs after our energetic day on the water. Full minutes will appear in due course on the SCRA website, so this is just a brief report with comments on matters that affect us on Seil.

The main thing that struck us in the Chairman’s report was the huge expansion in skiffing with there now being 24 clubs affiliated to SCRA, nearly 60 skiffs in Scotland and another 40 or so planned or building. Of interest to us are Tobermory with one or maybe two and Oban with maybe one, (although we haven’t heard anything from them for a while). Outside the meeting we heard that Luing are building, apparently following the successful charity row round the island.

Next year there could be a mid-Argyll regatta with eight or nine local skiffs plus visitors.

The Treasurer reported that SCRA is solvent, so the subscription stays at £60 per club.

The Committee will be co-opting a couple of new members including one from Argyll – details to follow.

The main business was consideration of the measurement rules. New rules will prevent imaginative builders producing an unfair advantage, perhaps at the expense of safety. I won’t record all the detail here, but happily Selkie is well within all the new tolerances, so we don’t need to alter her in any way.

Sensible amendments include allowing polypropylene for the keel rubbing strip, which we already have, also plastic or similar strips to reduce friction between oars and pins, which we should consider adding. They also clarify that our seat positions are legal, as is our rudder, although it’s not to the shape in the plans.

It was agreed that the expansion of the class means these must be more rigorously enforced and we were reminded that spoon and asymmetric oars are not allowed.

Metal oarlocks, footrests etc remain banned, showing that Scottish skiffing is building its own ethos that some may consider mildly eccentric.

I’ll write a further post with my views about what we should be doing this winter to improve our competitiveness, mainly addressing the oars and footrests.

Most important is to recruit some younger members, as half us rowing at Loch Venachar had bus passes. Here are some further images to let people know what they’re missing.

The Crowd before the startThe Crowd  againAnster ladiesChippy McNishCox RaySelkie ladies crewSelkie ladies in action

 

Issues for the 2013 AGM at Callander on 26 October

SCRA are just about to announce the details of the 2013 AGM, which will take place in Callander on 26 October at 1700 just after the Loch Vennacher sprint races finish.

This should be an extremely important meeting, as decisions will be taken that will affect the style of rowing and the type of competition that coastal rowing will be able to offer in the years to come.

In the four years since coastal rowing began a lot of experience has been gained, especially at the Skiffieworlds. The SCRA decided to cash on this and set up a Rules and Measurement Committee, which took soundings from clubs, inspected and in some cases weighed boats and set out some issues for discussion. The result was a set of summaries of the different issues, with questions added for the member clubs to decide. Our club should form a collective view on these, so that we can vote on 26 October.

The full report is on the SCR website here:-

http://scottishcoastalrowing.org/measurement-rules/2013-measurement-group-report/

You will see that various clubs are taking part already in an online discussion via the comments. It is open to both individuals and clubs to do this. We should all read the report and think about how we should respond. What follows is not to provide an excuse not to read it, so I will just summarise the main principles.

The Rules and Measurement Committee first asked itself what rules are for. We identified a number of quite distinct reasons why we need rules for boats in a class, mainly to ensure, safety, longevity of the skiff, fairness and “spirit”.

I’ve put spirit in quotes, because it’s still forming in coastal rowing and very important if often overlooked. There is a tendency in the existing rules to ascribe matters which truly belong to spirit, for example rowing with kabes or thole pins, to other things like saving money. This is patently untrue, as simple galvanised oarlocks are cheaper in the long run than wooden pins.

By spirit I mean the range of emotional factors that surround the St Ayles skiffs and their communities. It’s a mixture of nostalgia reflecting the history of the boat type and shape plus the unique elements that make them attractive and in time will become a tradition.

Traditions all start somewhere, usually for good reasons which get lost as time passes. All sports have them, both good and bad. Good reasons tend to reinforce the sense of belonging to a community, bad ones lead to exclusivity (e.g. certain bowling and golf clubs). In a sport one often does things for no obvious practical reason – that’s not what sports are about.

These factors are also part of the reasons why people take up our type of rowing as opposed to others. Alec Jordan for example records “At Hobart someone made a comment that these boats are a wonderful change from the testosterone fuelled misogyny of the surf boats”.

This leads directly into the main questions that members will want to discuss.

The most important are the issues about metal oarlocks versus clever wooden imitations of carbon fibre racing fittings versus thole pins versus kabes. Should SCRA ban feathering?

Other matters that will be decided are:-

Minimum Weight

Adhering to the drawings

Exotic Materials – e.g. the use of of polyprop for rubbing strips, technically illegal but most of us have done it.

Rudders

Footrests

Of course we will have personal views, but I understand that there will be one vote per club. We have no time to lose in opening a discussion.

 

 

Measurement Rules

The SCRA Measurement Rules Sub-committee recently reported and comments are being sought on the main website here http://scottishcoastalrowing.org/2013/09/04/measurement-rules-update/#comments

You’ll see that at the AGM a number of questions will be put to the membership based on the report, with new rules to be drafted later once decisions on the principles have been made.

Enjoyment of our unique form of recreation depends on carefully preserving a blend of keeping the rowing safe, healthy and comfortable on the one hand and respecting the heritage which produced the skiffs and developing the St Ayles spirit and style on the other.

We can take part individually in the online discussion on the main website, but we should also be discussing the various issues locally, so that when they go to a vote we have a view that we are all happy with.