One of these types of bridges:

Question: Is there a change in the load on the bridge as the barge goes across?

My guess is not because the barge displaces the same of water as its weight. But I just want to check.

party_pants said:

One of these types of bridges:

Question: Is there a change in the load on the bridge as the barge goes across?

My guess is not because the barge displaces the same of water as its weight. But I just want to check.

No change.

party_pants said:

One of these types of bridges:

Question: Is there a change in the load on the bridge as the barge goes across?

My guess is not because the barge displaces the same of water as its weight. But I just want to check.

To0 much weight on this bridge that causes it to collapse is called a Fargin

AwesomeO said:

party_pants said:

One of these types of bridges:
https://www.willemen.be/sites/default/files/styles/projects-page-slide/public/pont%20canal.jpg?itok=B2j-eCag

Question: Is there a change in the load on the bridge as the barge goes across?

My guess is not because the barge displaces the same of water as its weight. But I just want to check.

No change.

There will be some change. The displaced water has to go somewhere, so as the barge passes over bridge it will raise the average water level.

The Rev Dodgson said:

AwesomeO said:

party_pants said:

One of these types of bridges:
https://www.willemen.be/sites/default/files/styles/projects-page-slide/public/pont%20canal.jpg?itok=B2j-eCag

Question: Is there a change in the load on the bridge as the barge goes across?

My guess is not because the barge displaces the same of water as its weight. But I just want to check.

No change.

There will be some change. The displaced water has to go somewhere, so as the barge passes over bridge it will raise the average water level.

Does that change the load?

The Rev Dodgson said:

AwesomeO said:

party_pants said:

One of these types of bridges:
https://www.willemen.be/sites/default/files/styles/projects-page-slide/public/pont%20canal.jpg?itok=B2j-eCag

Question: Is there a change in the load on the bridge as the barge goes across?

My guess is not because the barge displaces the same of water as its weight. But I just want to check.

No change.

There will be some change. The displaced water has to go somewhere, so as the barge passes over bridge it will raise the average water level.

yes, my thinking. wouldn’t want to measure it though.

Wonder what happens if the bridge fails/barge crashes through the side etc
Is there any way of ‘turning off the tap’ so to speak or do the people underneath have to invest in floaties?

The Rev Dodgson said:

AwesomeO said:

party_pants said:

One of these types of bridges:
https://www.willemen.be/sites/default/files/styles/projects-page-slide/public/pont%20canal.jpg?itok=B2j-eCag

Question: Is there a change in the load on the bridge as the barge goes across?

My guess is not because the barge displaces the same of water as its weight. But I just want to check.

No change.

There will be some change. The displaced water has to go somewhere, so as the barge passes over bridge it will raise the average water level.

wouldn’t it just flow out the ends of the bridge into the main part of the canal?

The Rev Dodgson said:

AwesomeO said:

party_pants said:

One of these types of bridges:
https://www.willemen.be/sites/default/files/styles/projects-page-slide/public/pont%20canal.jpg?itok=B2j-eCag

Question: Is there a change in the load on the bridge as the barge goes across?

My guess is not because the barge displaces the same of water as its weight. But I just want to check.

No change.

There will be some change. The displaced water has to go somewhere, so as the barge passes over bridge it will raise the average water level.

That could depend on the shape of the water.

AwesomeO said:

The Rev Dodgson said:

AwesomeO said:

No change.

There will be some change. The displaced water has to go somewhere, so as the barge passes over bridge it will raise the average water level.

Does that change the load?

Why wouldn’t it?

You have the same amount of water + the boat. If the boat stopped in the middle of the bridge the water would eventually return to its original level, as the displaced water flowed out either end. At that stage the total weight would be the same as before the boat arrived.

party_pants said:

The Rev Dodgson said:

AwesomeO said:

No change.

There will be some change. The displaced water has to go somewhere, so as the barge passes over bridge it will raise the average water level.

wouldn’t it just flow out the ends of the bridge into the main part of the canal?

Yes, but that takes time.

The Rev Dodgson said:

party_pants said:

The Rev Dodgson said:

There will be some change. The displaced water has to go somewhere, so as the barge passes over bridge it will raise the average water level.

wouldn’t it just flow out the ends of the bridge into the main part of the canal?

Yes, but that takes time.

It also takes time for the barge to get onto the bridge.

Peak Warming Man said:

The Rev Dodgson said:

AwesomeO said:

No change.

There will be some change. The displaced water has to go somewhere, so as the barge passes over bridge it will raise the average water level.

That could depend on the shape of the water.

off the back…

To summarise.

To first order no change.

But small extra loads due to transient effects, movement of water due to the passage of the ship.

Much the same as the situation of the truck filled with pigeons on a weighbridge. To first order no change in weight but small transient effects due to the accelerations of the pigeons.

Michael V said:

The Rev Dodgson said:

party_pants said:

wouldn’t it just flow out the ends of the bridge into the main part of the canal?

Yes, but that takes time.

It also takes time for the barge to get onto the bridge.

It’s only a matter of time. It’s only a matter of time.

Michael V said:

The Rev Dodgson said:

party_pants said:

wouldn’t it just flow out the ends of the bridge into the main part of the canal?

Yes, but that takes time.

It also takes time for the barge to get onto the bridge.

But the barge is solid, has momentum, and is travelling along with a water wave in the same direction, whereas the water on the bridge is stationary, and liquid, so it can’t move until there is a pressure difference, so it will take a lot longer for the water to get off the bridge than for the barge + wave to get on.

The Rev Dodgson said:

Michael V said:

The Rev Dodgson said:

Yes, but that takes time.

It also takes time for the barge to get onto the bridge.

But the barge is solid, has momentum, and is travelling along with a water wave in the same direction, whereas the water on the bridge is stationary, and liquid, so it can’t move until there is a pressure difference, so it will take a lot longer for the water to get off the bridge than for the barge + wave to get on.

If it wasn’t going to do that then the barge could possibly not get over the bridge?

mollwollfumble said:

To summarise.

To first order no change.

But small extra loads due to transient effects, movement of water due to the passage of the ship.

Much the same as the situation of the truck filled with pigeons on a weighbridge. To first order no change in weight but small transient effects due to the accelerations of the pigeons.

It’s a similar principle, but the pigeons would reach equilibrium much quicker than the barge.

roughbarked said:

The Rev Dodgson said:

Michael V said:

It also takes time for the barge to get onto the bridge.

But the barge is solid, has momentum, and is travelling along with a water wave in the same direction, whereas the water on the bridge is stationary, and liquid, so it can’t move until there is a pressure difference, so it will take a lot longer for the water to get off the bridge than for the barge + wave to get on.

If it wasn’t going to do that then the barge could possibly not get over the bridge?

Why wouldn’t it? The canal over the bridge is no different than the canal anywhere else, as far as the barge is concerned.

The Rev Dodgson said:

roughbarked said:

The Rev Dodgson said:

But the barge is solid, has momentum, and is travelling along with a water wave in the same direction, whereas the water on the bridge is stationary, and liquid, so it can’t move until there is a pressure difference, so it will take a lot longer for the water to get off the bridge than for the barge + wave to get on.

If it wasn’t going to do that then the barge could possibly not get over the bridge?

Why wouldn’t it? The canal over the bridge is no different than the canal anywhere else, as far as the barge is concerned.

What I meant was that if the water decided not to displace for the barge. It was hypthetical if that works.

The Rev Dodgson said:

mollwollfumble said:

To summarise.

To first order no change.

But small extra loads due to transient effects, movement of water due to the passage of the ship.

Much the same as the situation of the truck filled with pigeons on a weighbridge. To first order no change in weight but small transient effects due to the accelerations of the pigeons.

It’s a similar principle, but the pigeons would reach equilibrium more quickly than the barge.

fixed.

roughbarked said:

The Rev Dodgson said:

roughbarked said:

If it wasn’t going to do that then the barge could possibly not get over the bridge?

Why wouldn’t it? The canal over the bridge is no different than the canal anywhere else, as far as the barge is concerned.

What I meant was that if the water decided not to displace for the barge. It was hypthetical if that works.

Could happen.

If the water was below 273 K.

The Rev Dodgson said:

Michael V said:

The Rev Dodgson said:

Yes, but that takes time.

It also takes time for the barge to get onto the bridge.

But the barge is solid, has momentum, and is travelling along with a water wave in the same direction, whereas the water on the bridge is stationary, and liquid, so it can’t move until there is a pressure difference, so it will take a lot longer for the water to get off the bridge than for the barge + wave to get on.

“A lot” is a value judgement. As a geologist, I see “a lot” of time to be around 500 million years. I imagine you’d see “a lot” as quite a bit less. Hours? Minutes? Seconds? Milliseconds?

If the barge sunk it would then displace a lot less water.

roughbarked said:

The Rev Dodgson said:

mollwollfumble said:

To summarise.

To first order no change.

But small extra loads due to transient effects, movement of water due to the passage of the ship.

Much the same as the situation of the truck filled with pigeons on a weighbridge. To first order no change in weight but small transient effects due to the accelerations of the pigeons.

It’s a similar principle, but the pigeons would reach equilibrium more quickly than the barge.

fixed.

No, unfixed.

Peak Warming Man said:

If the barge sunk it would then displace a lot less water.

That’s an interesting question – what if the barge sank on the bridge

Michael V said:

The Rev Dodgson said:

Michael V said:

It also takes time for the barge to get onto the bridge.

But the barge is solid, has momentum, and is travelling along with a water wave in the same direction, whereas the water on the bridge is stationary, and liquid, so it can’t move until there is a pressure difference, so it will take a lot longer for the water to get off the bridge than for the barge + wave to get on.

“A lot” is a value judgement. As a geologist, I see “a lot” of time to be around 500 million years. I imagine you’d see “a lot” as quite a bit less. Hours? Minutes? Seconds? Milliseconds?

Don’t need time units, it’s relative. It will take more than 10x longer for the water to reach equilibrium than for the barge, so there will be a significant change in weight.

Peak Warming Man said:

If the barge sunk it would then displace a lot less water.

But one could work out the SG of the barge if one had a good set of scales.

Peak Warming Man said:

If the barge sunk it would then displace a lot less water.

Not if it was a wooden barge.

The Rev Dodgson said:

Peak Warming Man said:

If the barge sunk it would then displace a lot less water.

Not if it was a wooden barge.

That would depend on it’s cargo and ballast.

The Rev Dodgson said:

Michael V said:

The Rev Dodgson said:

But the barge is solid, has momentum, and is travelling along with a water wave in the same direction, whereas the water on the bridge is stationary, and liquid, so it can’t move until there is a pressure difference, so it will take a lot longer for the water to get off the bridge than for the barge + wave to get on.

“A lot” is a value judgement. As a geologist, I see “a lot” of time to be around 500 million years. I imagine you’d see “a lot” as quite a bit less. Hours? Minutes? Seconds? Milliseconds?

Don’t need time units, it’s relative. It will take more than 10x longer for the water to reach equilibrium than for the barge, so there will be a significant change in weight.

I think I don’t understand. You seem to be saying that if it took the barge a million years to get fully on to the bridge, it’s take more than 10 million years for the water to reach equilibrium. Or if it took 1 hour to get onto the bridge, it’d be more than ten hours for the water to reach equilibrium. But if it came on really fast – say ten seconds – that it’d be a bit under 2 minutes to reach equilibrium.

Michael V said:

The Rev Dodgson said:

Michael V said:

“A lot” is a value judgement. As a geologist, I see “a lot” of time to be around 500 million years. I imagine you’d see “a lot” as quite a bit less. Hours? Minutes? Seconds? Milliseconds?

Don’t need time units, it’s relative. It will take more than 10x longer for the water to reach equilibrium than for the barge, so there will be a significant change in weight.

I think I don’t understand. You seem to be saying that if it took the barge a million years to get fully on to the bridge, it’s take more than 10 million years for the water to reach equilibrium. Or if it took 1 hour to get onto the bridge, it’d be more than ten hours for the water to reach equilibrium. But if it came on really fast – say ten seconds – that it’d be a bit under 2 minutes to reach equilibrium.

Not what I meant.

I meant that at normal barge speeds it would be at least 10x quicker getting on than the water would be getting off, so we don’t need to worry about illions of years, or even hours.

The Rev Dodgson said:

Michael V said:

The Rev Dodgson said:

Don’t need time units, it’s relative. It will take more than 10x longer for the water to reach equilibrium than for the barge, so there will be a significant change in weight.

I think I don’t understand. You seem to be saying that if it took the barge a million years to get fully on to the bridge, it’s take more than 10 million years for the water to reach equilibrium. Or if it took 1 hour to get onto the bridge, it’d be more than ten hours for the water to reach equilibrium. But if it came on really fast – say ten seconds – that it’d be a bit under 2 minutes to reach equilibrium.

Not what I meant.

I meant that at normal barge speeds it would be at least 10x quicker getting on than the water would be getting off, so we don’t need to worry about illions of years, or even hours.

Cheers.

Minutes or less, then.

Are we talking about the near canal here?

Woodie said:

Are we talking about the near canal here?

Now now…..

Woodie said:

Are we talking about the near canal here?

I think it was distant.

The Rev Dodgson said:

Woodie said:

Are we talking about the near canal here?

I think it was distant.

For me this inevitably brings The Two Ronnies to mind.

Oh I lost my little sweetie pie in Venice (pie in Venice)
Let me warn you, never go there with a gal (with a gal)
For those gondoliers they really are a menace (are a menace)
As they ply their trade along that far canal (fancy that!).

I copped a ban at the old forum for using the far canal pun in a thread title. It was to do with the then WA opposition leader’s election promise to build a 3000+ km canal from the Kimberly region to the Perth region.

party_pants said:

I copped a ban at the old forum for using the far canal pun in a thread title. It was to do with the then WA opposition leader’s election promise to build a 3000+ km canal from the Kimberly region to the Perth region.

I vaguely remember that (the canal, not you being banned).

Was this far canal to have a great big wall on the Eastern bank as well?

you can say anything you like in this forum….

Arts said:

you can say anything you like in this forum….

That’s good.

On the old one I had to refer to the great Australian entreprener as “Thingy Smith”.

The Rev Dodgson said:

party_pants said:

I copped a ban at the old forum for using the far canal pun in a thread title. It was to do with the then WA opposition leader’s election promise to build a 3000+ km canal from the Kimberly region to the Perth region.

I vaguely remember that (the canal, not you being banned).

Was this far canal to have a great big wall on the Eastern bank as well?

Only if the Eastern states paid for it :)

mollwollfumble said:

Arts said:

you can say anything you like in this forum….

That’s good.

On the old one I had to refer to the great Australian entreprener as “Thingy Smith”.

I think, as much as possible, we should experiment and see where the boundaries are…

Arts said:

mollwollfumble said:

Arts said:

you can say anything you like in this forum….

That’s good.

On the old one I had to refer to the great Australian entreprener as “Thingy Smith”.

I think, as much as possible, we should experiment and see where the boundaries are…

that suggestion is beyond the pale.

Bogsnorkler said:

Arts said:

mollwollfumble said:

That’s good.

On the old one I had to refer to the great Australian entreprener as “Thingy Smith”.

I think, as much as possible, we should experiment and see where the boundaries are…

that suggestion is beyond the pale.

like fuck it is

Arts said:

mollwollfumble said:

Arts said:

you can say anything you like in this forum….

That’s good.

On the old one I had to refer to the great Australian entreprener as “Thingy Smith”.

I think, as much as possible, we should experiment and see where the boundaries are…

No. Uncouth language is uncalled for.

Arts said:

Bogsnorkler said:

Arts said:

I think, as much as possible, we should experiment and see where the boundaries are…

that suggestion is beyond the pale.

like fuck it is

oh burn.

mollwollfumble said:

Arts said:

you can say anything you like in this forum….

That’s good.

On the old one I had to refer to the great Australian entreprener as “Thingy Smith”.

You talkin’ about Dick’s Myth?

sibeen said:

Arts said:

mollwollfumble said:

That’s good.

On the old one I had to refer to the great Australian entreprener as “Thingy Smith”.

I think, as much as possible, we should experiment and see where the boundaries are…

No. Uncouth language is uncalled for.

no really, you’re right, I should follow your lead.

mollwollfumble said:

Arts said:

you can say anything you like in this forum….

That’s good.

On the old one I had to refer to the great Australian entreprener as “Thingy Smith”.

Gone are the days when you could go into your ocal Richard Smiths Electronics Boutique and buy a resistor or two.

if I were The Lab, I’d burn this whole place down and fit it out with new stuff, then have a grand reopening

party_pants said:

mollwollfumble said:

Arts said:

you can say anything you like in this forum….

That’s good.

On the old one I had to refer to the great Australian entreprener as “Thingy Smith”.

Gone are the days when you could go into your ocal Richard Smiths Electronics Boutique and buy a resistor or two.

you can still do that…
you just have to take the tv apart yourself…

Arts said:

if I were The Lab, I’d burn this whole place down and fit it out with new stuff, then have a grand reopening

We worry about you some days….

party_pants said:

Arts said:

if I were The Lab, I’d burn this whole place down and fit it out with new stuff, then have a grand reopening

We worry about you some days….

those are the days I just need to be silly.. I have a lot of confronting stuff to deal with in this course, so sometimes just being a goose is all I need…. and here is where it happens because this forum is full of gooses

Arts said:

party_pants said:

Arts said:

if I were The Lab, I’d burn this whole place down and fit it out with new stuff, then have a grand reopening

We worry about you some days….

those are the days I just need to be silly.. I have a lot of confronting stuff to deal with in this course, so sometimes just being a goose is all I need…. and here is where it happens because this forum is full of gooses

Arts said:

party_pants said:

Arts said:

if I were The Lab, I’d burn this whole place down and fit it out with new stuff, then have a grand reopening

We worry about you some days….

those are the days I just need to be silly.. I have a lot of confronting stuff to deal with in this course, so sometimes just being a goose is all I need…. and here is where it happens because this forum is full of gooses

Fairny nuff then, goose at will.