Richard Braithwaite

Continuing to add canopy sections. On the full size ship the sections were kept separate so as to minimise stress in the lightly built canopy as the ship flexed in a seaway. On the model I have left the outer rail continous so that alighment is maintained.

First section of canopy with the planking completed, showing brass pins at base of inner stanchions which engage in brass ferrules in the deck beams and brass bolts which hold secure the outer edge. and here it is mounted on the model:

Starting to plank the canopy today. Olympias's canopy was constructed from a number of sections so that the delicate structure would not be damaged by the hull girder stresses as the long thin ship flexed at sea. The sliding joint between each section is shown in the extract from John Coates Plan No 23 (Quarter Deck) below: The start of this joint is indicated by the arrow on the following picture of my model:

Since this is intended as a model of "Olympias" rather than an updated attempt to model an Athenian Trireme, I shall stick to the Olympias Ram. As a parallel project, I am also working on a software simulation of the maneuvering of oared warships, which I am validating against the sea trials of Olympias. One of the original ideas was to use this model for testing to find some of the coefficients for the software simulation. Must admit that I got a bit carried away with the model. Rather more detail than would be strictly required for a tank test model... I (sort of) justified it to myself on the basis that If I built it to the full size drawings, from wood of the same density, then the weight distribution would be about right.... But there are easier ways of doing that. Probably also easier to use Computational Fluid Dynamics Software to derive the coefficients. Anyway, I thought it would be fun to see if I could build an accurate enough model of Olympias at this scale and fit a rowing machine in it. Haven't yet decided how I will make the ram... John Coates "Plan No 20 Trieres Ram" drawing shows details of the wooden structure (which I have used for my model as you can see from the whole ship picture at the beginning of the blog) but does not detail the construction of the "Ram Sheath" other than to say that is based on the Athlit Ram as described in the Mariners Mirror , August 1983. The views in the drawing suggest that it is fabricated from plate. Part view of Plan No 20: Ill need to do some more research...

Yes, remains to be seen whether I can achieve the required level of accuracy. Placement of the thole pins in relation to the oar ports is critical to achieving the required length of stroke. The following photos show the approach I used: 1. A jig used for drilling the thole pin mounting blocks to ensure that the hole is in the right place and angle: 2. Some pins installed on their blocks together with a jig for installing at the correct angle in the boat: 3. Installing the pin in position using the jig: 4. The pin in position: 5. Finally, a check on the clearances to give the required stroke angle:

I've used lime pretty much throughout, mainly because the density is close to that of the pine used for the full scale reconstruction. Its quite a soft wood (compared to fruitwoods such as holly or pear), but that doesn't seem to have been too much of a problem and it has a very fine grain, which is nice..

Before I embarked on this project I built a section model to see if I could fit machinery below the central walkway to operate the oars. This remains an option for this model which is why the canopy and internal hull structure is removable (see bolts in the above pics). The machinery is quite crude (I would aim to improve on that with the full model) but did demonstrate that independent control of port and starboard oars would be possible with machinery that would give an elliptical oar path with the right stroke length.

There are 170 oars on Olympias. One of the purposes of the reconstruction was to demonstrate that that many oars could be operated effectively from a 37m long vessel... The oar system arrangement can be seen from the following extracts from John Coates Midship Section drawing:

Some more pictures of the canopy framing:

Several years ago (quite a few in fact...) I started building a 1:24 scale model of a reconstruction of an Athenian Trireme. The model is based on drawings produced by John Coats for building the full size reconstruction ("Olympias"). A number of trials were conducted with the ship in the 1980's, which have been published in a number of sources by the Trireme Trust. Well worth looking up. A fascinating example of experimental archaeology. I did have a blog running to record the model build (on this site I think?) but have not updated for a long time and I think it is no longer there. I have now reduced my working hours which has given me more time to progress the model over the last few months, so I thought it would be worth restarting the blog. I have just completed the framing for the canopy.