not really bushcraft but here's a nice bridge

[robin wood]

As they say on blue peter here's one I made earlier...2 years ago in fact.

They are both within 2 miles of home so checking bolts for tightness isn't a problem though the first one has not needed tightening yet. I have watched demos of scribing several times and Japanese framing but I am not a timber framer. I very much admire old framing particularly the roof trusses in the old barns round here, rustic but beautiful. I like wooden boat building too. Still not sure how housing would help keep upright in contact with beam as it shrinks? Sure it would give it more side to side rigidity but it gets that from the 3 rails anyway. One way I could think of that would keep upright in contact with beam without the bolt would be a proper joint, a dovetail or mortice and tennon both of which would need a considerably larger main beam to give space for the joint and still leave enough tread to walk on.

I am relying on a single large bolt but it is well tested technology, the principle rafters in my barn are scarfed with just such a bolt (150 yrs plus old), another bridge in Edale built about 50 years ago has similar threaded bar plus nuts to hold the uprights on and its going strong.

 

[jojo]

Although the wood will shrink, it will also expand, depending on what the level of humidity is. I should think that over the months the cycles of shrinking and expanding will balance each other out. So it's not so likely the joints would loosen so much that it would weaken the structure. The main beam is so substancial that it would alone maintain the integrity of the bridge. With the vertical stanchions and the 3 rows of rails on each sides, copper riveted together, that is a very strong, self supporting structure. Even if the bolts were completely loose, I should think the bridge would stay together

 

[Owen Bush]

I really like that bridge ,that is a very simpathetic river crossing .

 

[addo]

Yet another great reason to go to Edale, as well as the walk and ale.

 

[DoctorSpoon]

ale??? either you struck lucky or you work up such a thirst walking it slides down without you noticing the taste!

 

[rich59]

Just wondering about the curved shape of the bridge. Will it sag with time or is there compression from the ends to counteract the weight?

 

[robin wood]

all the tie beams in the barns round here (the ones over 100 years old) have very similar shape, it gives a bit more clearance under the beam and makes it stronger than a straight one of the same size.