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.

 

Circumnavigation of Seil, and Ceilidh, 11 June

This year’s regatta is a circumnavigation of the Isle of Seil, anti-clockwise, on Saturday 11 June, starting from Balvicar at 0900, Hunters Quay at 0930. Crews which have confirmed so far are Selkie, Isle of Mull, Pittenweem and the Isle of Luing. We hope to shoot the bridge around 1000.

A ceildh will be held in the Seil Island Hall in the evening. A buffet will start at 1900, and the ceilidh at 2000. Live music will be performed by Seil Sound and by The Brother. There will be a raffle and a pay bar. For details see the regatta tab above; tickets are now available from Balvicar Stores.

Fundraising such as this helps keep our membership costs down. This year, we would like to make a new set of longer oars and have more comfy seats to help alleviate ‘rowbot’ as well as undertaking general maintenance on the hull and cover.

See you on the water, and/or at the Ceilidh! All welcome.

We’ve got a Trolley

trolleydollyOnce again we’ve picked the brains of the Ullapool people and copied their ideas for a trolley, which is 90% there, just needing some paint, some scrap carpet glued to the supporting pads and the axles drilled to take big washers and pins to stop the wheels falling off.

Image completed by Sue, fighting fit from the worlds in her new St Ayles skiff teeshirt. Which reminds us, serious work now needed to organise teeshirts, hoodies,car stickers and our flag. 

 

Rules – What are they for? What is their status?

Our new very legal rudder
Our new very legal rudder

I’m sure that most of us just want to go rowing, but there are some sad people who think about dry and dusty things like the rules. Later this year when we go to the Skiffieworlds there will probably be quite a few who are not just sad but a little upset as well, because we are likely to see modifications in construction that we discussed during our own build but rejected as outwith the spirit of Scottish Coastal Rowing.

The viral growth of the fleet has taken everyone by surprise and it’s clear that the measurement rules would have been much more tightly drawn had this been anticipated. As a result SCRA has commissioned a full review of the rules with a view to bringing in amendments for discussion at a future AGM. I am a member of the group charged with considering the existing rules, gathering views and offering advice.

All of us on the group are wearing two hats, because we are also involved in our own clubs and want to win races. Now that we at Seil are on the water and gaining our own experience we should be thinking about the issues surrounding the rules, so that we can adopt a position at any future SCRA meetings where amendments are discussed. I’m posting about some of the issues, in the hope that it will stimulate thought and perhaps a bit of discussion through comments.

I suggest that it’s possible to identify a number of quite distinct reasons why we need rules for boats in a class. I can think of four, safety, strength, speed and spirit. There may be a fifth that spoils the alliteration, cost, but with the kit-built skiffs I suspect it’s less important than we think, as the big items are all fixed.

I won’t waste time describing why the first three are important. By spirit I mean the range of emotional factors that have come together in the last three years or so surrounding 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 for a variety of reasons, good and bad. Good reasons tend to reinforce the sense of belonging to a community, bad ones lead to exclusivity (c.f. certain bowling and golf clubs). We’ve all come across this, probably without actually acknowledging that in a sport one can do things for no obvious practical reason.

In our rules group I have argued that we should be aware of the importance of spirit and not shy away from promoting it as a value. It’s actually the only reason why any of us would take to the water in an attractive, slightly old-fashioned looking wooden boat with oars hanging off wooden thole pins and a flag pole on the front. Otherwise we’d be scooting about on sliding seats in carbon fibre contraptions and probably wearing designer lycra.

As we all know, the concept of the St Ayles skiff was developed at the Anstruther Fisheries Museum to commemorate certain traditions and perhaps revive them. In no particular order the historical antecedents were:

Scandinavian, ultimately Viking, boat shapes.

Historical Scottish fishing practice.

Recreational and competitive rowing in our east coast towns, particularly among the miners, but also on the west coast and island communities.

Traditional styles of rowing with long oars, kabes or thole pins.

The rules as presently expressed do refer to the spirit of the St Ayles skiffs, but there is a lack of detail, also an apparent reluctance to be open about the importance of this. As a result particular provisions designed to entrench the spirit have been justified on the other grounds, safety, strength speed and cost.

In the group I have argued that we should have the courage to acknowledge that rules making a boat strong may have nothing to do with safety, rules about speed may have nothing to do with either of those and rules about spirit absolutely nothing to do with any of the others.

Some of the issues are fairly clear. For example as we learned during the build adding rocker by reducing the keel at the ends is not allowed. Others are less so. Here are some of them.

Rowlocks.

The rule requiring these to be of wood has been justified on cost grounds, but metal crutches are demonstrably cheaper and longer lasting that wooden pins or kabes. Also some clubs have made clever wooden imitations of carbon fibre racing fittings, enabling oars to be feathered.

Feathering oars.

As a consequence of clever woodwork feathering has become possible and seems to be within the current rules. We have to think about whether or not this is the style of rowing the clubs (and we personally) want to see.

Should feathering oars be banned? On balance my personal view is, yes, they should be. I would argue that the traditional system with kabes or pins is central to the experience and much easier for inexperienced rowers to master. My views might change after a lot of hard upwind work though.

Spoon blades/choppers

Spoons are disallowed, ostensibly on cost grounds. That justification doesn’t stand up, because it’s cheap and easy to laminate curved blades using the same procedure as we did with the stems. It seems truly a question of spirit.

Materials

The existing rules allow a number of specified traditional materials apart from wood – Brass, Silicon Bronze, Stainless Steel, Gunmetal” and go on to say “The only synthetic material permitted in the boat construction is the glue which should be of Marine Quality, and will usually be Epoxy resin or a Polyurethane glue”.

I think everyone has problems with the letter of this. Our polypropylene strips are illegal, but most skiffs have something similar, as bronze ones cost about £300. One recent skiff is said to have stainless steel thole pins, done with no intention to gain an advantage.

Footrests are not shown in the plans, but are necessary for rowing efficiently. A discussion is ongoing about the extent to which they may incorporate metal adjusting/strengthening strips.

Rudders

Alec Jordan’s original view was that the design should be completely open, to allow ideas to develop. During our build we discussed how it would be better for the pintles to be in a vertical line to the water and how this could be done with an outrigger. We decided not to do this and to keep the leading edge following the aft stem. Given the lack of a rule banning outriggers it will be interesting to see what people turn up at Ullapool with.

Later this year clubs will be asked to comment on these issues and if they want to entrench some basic principles which would purely be intended to preserve the spirit of inclusive community participation and the obvious good things that are causing this project to grow so quickly. It will be interesting to see what each regards as important to the experience of being involved with the St Ayles skiffs. We should be thinking about our own contribution to this. I await our own discussion with interest.

 

  

The Final Job List

The trouble with any building project is that as it nears completion the to-do list gets longer and longer. At least with the hull nearly painted we’re very much in the last lap with only a few big jobs left but quite a number of little ones.

There’s one footbrace done and ready to be painted.

OLYMPUS DIGITAL CAMERA

Two more of these are required to complete the set.

There’s a rudder ready to receive its fittings.

OLYMPUS DIGITAL CAMERA

It has a transverse tiller, to which will be attached a fore and aft extension with a universal joint. This should be much more comfortable than what most are using, involving either a bent tiller or a yoke with steering lines. Time will tell whether it works or not.

We lack a trolley, about which see comments at the end of the last post.

Other items may be beyond our ability to make, such as a boat cover and the road trailer.

Wednesday’s painting didn’t happen

No painting today for two reasons.

Firstly, only two people turned up. The minimum number to comfortably do the inside of the boat in a session is three.

Secondly, the undercoat was still a bit soft. Paint had pooled between the stems and the planks near the keel fore and aft, and any runs were too soft to really sand down satisfactorily.

David and I scraped out the worst of the the wet stuff down the side of the stems then sanded the first coat of undercoat down  and wiped it down with white spirit. Another  quick wipe should be all that is needed before painting on Sunday.

We really need to start geting two coats a week on now – Sundays and Wednesdays – so more hands are urgently needed for the painting team if we are to launch in May. We also need some more fine sandpaper. Fine should be all we will be using on the paint from now on.