Trireme Olympias by Richard Braithwaite

[Richard Braithwaite]

1 hour ago, Chuck said:

Lovely....

 

And you are using Basswood?  or Lime?

 

So nice.

Mostly lime with some use of holly for intricate bits like thrbtriarch's chair

[BANYAN]

An excellent result Richard, they look great in situ with the glass reflecting the hull.

 

cheers

 

Pat

[Richard Braithwaite]

I've been thinking about how to secure the oars to the thole pins. During the first trials leather loops were used, but these tended to stretch as they got wet so in 1994 an adjustable rope grommet was introduced on the advice of a Poros fisherman (Ref The Athenian Trireme, Coats et al). I have used some thinned down leather for my steering oar bearings but am not sure of the longevity of using real leather in this application so will probable go with the 1994 rope version. Here is its using Ben's 0.5mm polyester rope (12mm full scale), which seems about right. In the Illustration "the stopper knot at one end of the grommet has been pulled clear for clarity". Mine is pulled up tight...

Still getting to grips with this small scale ropework. One of the things I've realised is the amount of wastage one requires, just to give you something to hold onto. Its very fiddly stuff!

 

I'm going to have to order some more rope to make sure I have enough...

 

Edited September 17 by Richard Braithwaite

[Veszett Roka]

This is an interesting knot. Hard to imagine how they knot it, which end is starting and which one is the finish line. I guess you have to lift up the three round and put the end under them? 

[Richard Braithwaite]

Basically 3 turns starting at the stopper end then a clove hitch.

[Richard Braithwaite]

Dan (dicero) has kindly invited me to do an online presentation on this project for  the NRG on October 11. I'm planning to include the background to the project and the construction of the hull, which all came before I started this build log and will do my best to answer any questions you have.

[kurtvd19]

All NRG members will be getting their invitations with the ZOOM link later today.  This promises to be a great presentation.

Kurt

[Richard Braithwaite]

For some time I've been considering whether to cast the ram (like the archaeological Athlit Ram) or fabricate from plate (as was done on Olympias). Recently I had a go at estimating the weight and determined that the majority of the sheath needs to be 0.2mm brass (equivalent to 5mm plate full size). That excludes casting since the minimum achievable wall thickness seems to be around 0.6mm. 

So, the next thing is to determine how Im going to put it together and out of how many pieces...

I've produced this former to look at the feasibility of shaping a single piece of 0.2mm brass for the top part of the sheath. First attempt in 0.1mm copper shown alongside the former. This worked quite well without any annealing. first attempts with brass have been difficult but, hopefully some more thorough annealing will make it work. Otherwise its two pieces with an overlap over the top. Either way Im going to end up with a lot of soldering stages so we'll have to see how that will work out...

 

[BANYAN]

Looks good Richard.  Why not use the copper one?  

 

cheers

 

Pat

[Richard Braithwaite]

The copper is a bit thin for brazing, but it does seem more maleable, so a copper ram might work (not sure about colour, although i could always get it electro plated...)

[Richard Braithwaite]

The answer, of course, is get a bigger blowtorch...

 

My little Dremel blowtorch wasn't capable of heating the whole piece up enough to anneal it sufficiently. Last night I got a really hot (open) coal fire going and tried to use that. Placing the piece amongst the glowing coals did generate enough heat to get it glowing red hot, but it was difficult to control and I ended up melting the ends of two attempts.

 

So today i bought a bigger blowtorch (the one on the left). That did the trick. Plenty of heat to get the piece red hot with sufficient control to avoid melting any of it...

The results of about 15 cycles of heating a piece of 0.2mm thick brass sheet to red hot, quenching in water and bashing with a brass hammer over my former can be seen below. Not quite trimmed to fit yet, but I've achieved the shape I need...

 

 

 

[Michael Mash]

After reading about your Blowtorches, Coal Fires and Hammer bashing, I send an enthusiastic round of applause. I think this is how they (The Greeks) would have done it!

Humor aside, your ram looks good, and this project deserves the effort you are putting into it.   

Mike

Edited Wednesday at 04:51 PM by Michael Mash

[Kauz]

Hello,

don't know if you are aware that there are different brass alloys. Gross categories are hard, semi hard, soft. You might look for a material suitable for deep drawing, this should be quite malleable and soft. Not as soft as copper, however. Silver would be another option, but with price nowadays ... , and you'd have to cope with the colour 😎.