A Tale of Two Sisters
Birgit and Astra II Revive Tore Holm's 1945 Design
These twin sister eights are both built according to Tore Holm’s drawings from 1945. The design was not turned into a boat that time. Instead, Birgit sailed first 2002 and flies the flag of Sweden for Lars Widén and Lars Blomgren of Stockholm. The detailed structural design of the boat was done by your TC-member David Viera of Absolute Restaurations in Lisbon, Portugal. Astra II is still under construction and is to be launched late 2006 for Mr Alexey Rusetsky from St Petersburg. The builder of both boats is a shipyard in St Petersburg.
What is special about this design is that it has been decided that anyone interested in building an eight for himself can build a sistership to this design. Just buy the plans, add your personal flavour to the cabintop and start carving wood. And yes, contact your TC before you do anything else.
Birgit and Astra II have given the TC ample opportunities for serious thinking. The most important issue has been the keel design. It turned out that the lead was much misplaced by Tore Holm thus making the boat extremely tail heavy. In the thirties this was actually not a very unusual happening when dipping in an eight for the first time. But Birgit was the first “new” classic eight to be dipped in for many decades so there was not much real life experience available to remind anyone interested that the flotation balance calculations should maybe need a bit of computer checking. So Birgit went in unchecked and needed some 250 kg of lead in front of the mast to sail at least somehow in balance.
The owner contacted the TC and asked if and how a new keel could be made. In the following exchange of information it become clear that the intention of the owner was not to produce a more modern keel but to just correct an apparent mistake as was often done in the thirties too. The TC even informed the owner that the proposed new keel may actually somewhat decrease the performance of the boat as the center of gravity of the lead was raised upward, and that if the owner would so desire, a possibly better keel shape could be copied from Tore Holm’s other designs, most notably from his sixes of the same era. The owner did not think this was very significant and so a new keel was cast according to a Russian design as per proposed to TC. With this new keel Birgit floats much better but unfortunately is still slightly tail-heavy, so some more trimming is needed. As in this case or any other similar case the recommendation of TC is to always cast a keel with a trim window. When deciding what is to be accepted when reforming the keel the TC took into account issues like the profile used, the radiuses of the edges and corners and the angle of the leading edge so that they all conform to a classic design typical to the era and designer. The TC is generally against reshaping a keel, and is to limit acceptance only to cases where a clear design mistake is evident.
Astra II shall be equipped with this same reshaped keel, but more emphasis will be put to keeping the tail of the boat as light as possible when building the hull.
The TC has helped Astra II in some other matters too, ranging from square weight issues to cabin skylight structures and wrought iron floor design.
The TC is eagerly waiting the Astra II to be finished and finally sailed against Birgit and other Baltic Fleet eights. So far Birgit has not been able to reach podium positions in the Baltic regattas, but that may well change when these very special twins and their crews are finally in top tune.
