Construction Techniques

Tightening Lashings with a Lever

As noted earlier, you need to use ropes and lashings to tie the raft together like they used for the Kon-Tiki Expedition across the Pacific.  You are not permitted to use nails, screws or staples since they were not invented during the period the expedition was emulating (approx 500AD).  We will allow drums for flotation since we don’t have a supply of balsa trunks.

Your lashings for the base and drums need to be strong enough to last a full day on the water without coming loose.  Nylon ropes tend to loosen over time, especially as the raft flexes on the water when the team moves about.  Manilla ropes expand slightly when they get wet and this makes the lashings stronger.

You can buy manilla rope from:

Schillings in Wingfield, tel: 8244 7611, who are Scout friendly. Peter is the contact. It must be three strand rope for the base.  We recommend 12mm manilla rope but recognise that 10mm manilla is much cheaper and you use it at your risk.  Sisal rope is also cheaper than manilla but much weaker, you use it at your risk – it is most likely to break when tightening with a lever.

It is best to use a frapping hammer as a lever to tighten the rope many times while you tie the lashing.  There is information about this process at http://ropesandpoles.blogspot.com/2007/02/tightening-lashings-using-frapping.html   Once you have used the lever to tighten after a turn, use a hand to hold that part tight while you complete and tighten the next turn.

Rope Ends & Finishing

The rope ends must be neat and you can’t use the burning method with manilla ropes, so this is a good time to practice whipping or back splicing the rope ends.

Please make sure the scouts whip lots of ropes but you don't need to whip them all.  You can finish many ropes by putting tape around the end.  This has the advantage that there are lots of whippings left for scouts the following years.  The tape method is quicker but may not last as well, so you can use this as a justification for doing more whipping the next year.

You need to avoid long lengths of rope dangling at the end of a lashing by finishing the lashings with a suitable knot.

Tying a Drum to the Frame

The best method to tie a drum to the frame securely is to use a truckie’s hitch, eg http://www.animatedknots.com/truckers/index.php

One technique is illustrated in the Cape Town photo below.  Notice they have used small blocks to hold the drum away from the pole, so the rope can slide around easily to tighten it.

Decking

Decking can be planks or wider materials but you will need to lash them together.  It is ok to drill holes at the edge of wide boards so you can lace them to the raft frame.  It is recommended to lace them with a blanket stitch and a lever to tighten it.

Construction Course

These techniques will be demonstrated at a training session nearer the time.  Please nominate a team expert or leader who will attend this session or learn the standard required from the web resources and then teach the raft team and support crew.