Barges

[Bigpub]

When a barge passes over an aqua duct what happens to the mass? Does its mass become neutral due to water displacement or is the mass transferred down the duct supporting columns?

[Space]

I didnt know you could put a barge into an aquaduct... but anyway:
The mass doesnt become neutral,
however the barge pushes away a large mass of water ( same mass as itself )
and that water is spread all along the aquaduct ( water level rises ),
so it's as if the weight of the barge was evenly distributed all along the aquaduct.

[Loosehead]

Assuming that the aquaduct is not blocked at both ends then the barge will displace it's weight in water throughout the entire system. This would effectively spread the weight over the whole water system and result in a microscopice rise in water level. So the barge would make a negligable difference to the actual weight on the aquaduct.

[Space]

Looshead's answer is more accurate than mine

[Hamish]

In fact most cannals have overfows call weers (not sure of spelling). these keep the water level almost constant - therefore as loosehead says there would effectievly be no increase in mass on the aquaduct.

[Peter Pedant]

Space - of course youcan put a barge in an aqueduct - happens every day in barton aqueduct. [Also famous for being a canal over a canal]

I agree the barge has displaced its own weight of water, sol long as it has nt sunk of course....

[landie]

The increased water pressure local to the barge hull will act on both sides of the trough, and the base. It will dissipate with distance but there will be a local loading on the supports.

We have a famous aquaduct near us at a place called Froncysyllte near Llangollen. It can be used by pedestrians as well as narrow boats as they are called.

[Bigpub]

I've been to that aquaduct Landie it's brilliant

[landie]

Yes it's quite a landmark and a lovely spot, Bigpub.

[Bigpub]

I can't believe i asked this question about 7 years ago. Thanks for all your brilliant answers