In article , Serenity serenity@nospa
mserenitynyespam.off.fslife.co.uk writes

serenitynyespam.off.fslife.co.uk writes
I need to get a bridge to span an 18ft dyke.

Is that 8? or do you really mean 18?


Yep an enormous span - 16ft sleepers won't cover it :-(
It is just to take people. No vehicles.


If you make it too wide, then at some time in the future, someone is
going to try to take a vehicle over it :-((

If you make it too narrow to prevent the above, then you must take into
account that at some time or other, it could be full of people and the
bending moment at the middle will be enormous, so it must be thick
enough to take in the stress and strain of its thickness material :-((

From the centre, will it be possible to take some support struts down at
an angle into the banks on either side?

Very difficult to judge just what would be suitable without a visit and
knowing what, how, why and wherefore :-((

Brick Arch from the bottom with a keystone?????

Mike

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