THE ARCH, A GREAT DESIGN

Using the template on the right, copy, cut & paste it into a word document.  size it to fit an A4 page with minimal margins.  Don't worry you can stretch and tweak it as required.   Printing eight  copies clue two butt stones and eight arch stone templates onto some thin card.  Cut them out and scoring the fold lines begin to assemble each box. Before sealing the last face of each box you need to weight them by means of some plasticine, marbles anything heavy. No need to do this with the butt stones

Now your ready to start building. Although the span of our arch was originally 30cm you have probably resized the template to fit your document.  We suggest you lay them out flat and using a ruler check the span between the inside edge of the two butt stones.  

These two butt stones are the only ones to require further gluing.  As indicated in the arch plan glue them to a piece of card the appropriate distance apart.  The remaining eight stones, under there own weight simply hold each together. Should you have trouble assembling these eight stones, you may find it helpful to cut a strip of card and bend it  in an arch between the butts stones to support the stones during construction.  Once the arch is built apply some firm pressure to the top and remove the construction strip of card. 

Try testing how much weight your bridge can hold.  We think you will be impressed.