Hoi Larntan has been in regular use –

Aside

Hoi Larntan has been in regular use – more outings than I can count. Some despite the wind and weather and one cancelled because of it!

Adrian has been re-modelling the first set of oars that he and Andy made, slimming them down and helping to make rowing even easier.

Collars of Oxford are making our second set and we have three further generous rowers to thank for their contributions – Professor Robin Forrest, Elaine Sassoon (our dedicated cox) and Antonia Hardcastle all of whom have braved the Norfolk winds to row regularly – somehow seems always to be against the tide too!

There are many others to thank for their practical help, Roy who even had his own boat altered so we could practise before Hoi Larntan was launched, Morris whose draughtman’s skills solved more than one problem and Ian Ruston who masterminded the clothing and logos (based on Godfrey Sayers and Adrian Taunton’s designs). Ian has also stirred up lots of support locally for us. Thanks to you all and others I have not yet mentioned.

Thursday and Friday this week sees our first major coaching sessions – Mike Gilbert is coming to put us through our paces – more after the event.

The cover has been made and looks good and robust:

 

Image

Oar Philosophy

 We built a set of oars for the St Ayles Skiff Hoi Larntan during the winter of 2012/13. The following notes may help rowers to understand why they are as they are.

 Length of oar

The original plans for the boat show a 12’ oar and the rowers sitting in the middle of their seats. But, there is an inherent problem with the St Ayles Skiff, because of its length and the distance between the seats. Other rowers have found that there is a tendency for the hands of one rower to collide with the back of the next rower if all sit in the midline of the boat. Other crews have overcome this problem by sitting alternately to port or starboard of the midline. This can be achieved by using oars, which are either longer, or shorter than 12’. With shorter oars, the rower sits toward the side with his kabe/thole pin and vice versa with longer oars.

Having measured the span of the boat at each rowing position and the distance between the seats, we chose to use oars with an inboard length of 33”, being the longest that would not cause collision.

We chose a gearing of 3:1 (outboard length : inboard length), which is almost universal in all types of rowing. The measurements being taken from the tip of the blade to the tholes (outboard length) and from the tholes to the end of the handle (inboard length). This gave an overall length 132” (inboard length (33”) X 4).

Since the span (distance from port thole to starboard thole) is different for each seat, with oars of the same length, the rowers do not sit equidistant from the midline of the boat. This has a consequence on the listing moment of the crew. If all the rowers are of the same weight and all have oars shorter than 12’, there will be a tendency for the boat to list to the side of the bow rower.

This could be compensated for by giving the stroke a shorter oar, thus moving him further away from the midline, but we chose to have all oars of the same length for simplicity and ease of replacement.

Of course all rowers are not the same weight and the listing moment problem can be alleviated to some extent by sitting the lightest rower in bow seat and the heaviest at 2.

Shape of blade

Traditional oars for sea going boats have long narrow blades. These are said to be easier to manage in rough water than wider blades. One of the consequences of a long narrow blade is that the centre of resistance to the water is further from the tip of the blade. This effectively reduces the gearing (see above).

Cornish gigs have now largely abandoned “traditional” pattern blades for modern designs based on those used in fine racing boats. These have been found to be more efficient in normal circumstances.

We have chosen a blade profile similar to one used by junior gig rowers, but without  a “spoon”,  which is not allowed under the rules of the SCRA.

Thole pins and collars.

Different St Ayles Skiff crews have adopted a variety of methods to link the oar to the boat at the gunnel. We have chosen to keep to the English tradition of a leather collar on the loom of the oar, with no button, lying between a pair of tholes.

In fact Hoi Larntan has a sort of hybrid system with the forward pin being replaced by a kabe, but it all works like a pair of thole pins.

This allows rowers to increase or decrease gearing by sliding the oar in or out.

Loom section

We have chosen a square cross section for the portion of the loom, which lies between the thole pins.  This effectively sets the angle of the blade in the water, when the rower pulls against the thole pin and the flat surface of the loom conforms to the face of the thole pin (kabe).  We thought that this would tend to reduce the twisting of the handle in the rower’s hands, which might be a consequence of the wider style of blade if used in rough water. We chose square rather than D section so that the oar could be used on either side of the boat with the stitching to the leathers facing up.

Length of handle

We chose a handle length of 16” as used on gig oars.

Wood

The SCRA bans carbon fibre and other “hi tech” materials from competition. Many high quality wooden oars are made from Sitka Spruce, which is strong and light, but expensive and not readily available locally. We used Douglas Fir, which although strong, is 30% more dense than Spruce (and half the price). Consequently the oars are heavier than they could have been.

Adrian Hodge

11th June 2013

We are in the process of deciding about another set of oars.  it would be really good to have some feedback as to what these should be like.  Adrian and Andy are keen to be sure we have not ignored a fundemental fact and gone off on a tangent!

Please let us know what you think

Phase II

After the excitement of the launch, and thanks to all who came and took part, Hoi Larntan has been out three times with different crews at Blakeney. A brief spell back in the workshop, then off to Beale Park near Reading to take pride of place on the Watercraft stand at the boat show. She created lots of interest and two sparks were ignited – one East Coast and the other West Country. We shall have to wait and see.

Chris Partridge of Langstone Cutters and  rowingforpleasure.blogspot.co.uk  fame took her out on the water and into the Thames for a lengthy row on the great river. Three more outings in all. Thanks to the crew from HBBR – the Home Built Boat Rally for muscle(?) power.

More thanks for great generosity from several sources which will allow us to have a spare set of oars made for Ullapool.

Long established accountancy firm Lovewell Blake LLP have offered a substantial gift. They have faithfully guided Alan Collett and the team during his time at the Litcham Health Centre and very kindly  are giving us a big chunk of the next set of oars. A huge thank you.

Dave Chambers at Norfolk Larder in Briston, apart from selling us fresh fish and delicious dressed crab, has also supported us generously in our quest for more oars. He takes a great interest in our efforts and is a good friend and ally. Thank you, Dave.

Barbara Ward Jones said she would be embarrassed if I mentioned her contribution too – so obviously I wouldn’t dream of doing so – but thanks very much to her anyway!

So many others are helping – we’ll get round to thanking you personally.

The scene at Beale:

Image