Coalition casualties for september

On Fri, 03 Oct 2003 17:56:05 GMT, "Gord Beaman" )
wrote:

"Brian Sharrock" wrote:

Now, go and check your tire pressures before the next rain shower.

Yep that's right...we used to use "nine times the sq root of the
tire pressure" for the onset of hydroplaning, which is about
right...you ever think about where a steel wheel rolling on a
flat steel surface will hydroplane?...

follow ups trimmed...

I doubt that the rail road rolling stock has much problem with
hydroplaning...

ck
--
The Ten Commandments display was removed from the Alabama Supreme Court
building, But here was a good reason for the move.*

You can't post "Thou Shalt Not Steal" in a building full of lawyers and
politicians without creating a hostile work environment.

Edna H. on alt.books.m-lackey, 20030930

On 2 Oct 2003 13:07:42 -0700, (Kevin Brooks)
wrote:


Changing tires can be nasty business, and not (as Vkince seems to
believe) only in the military. Care and common sense are required--it
has long been the practice in the US Army to require use of a "tire
cage" (a stout steel frame/cage) during inflation of tires. In the
absence of a cage, while in the field and away from our parent unit, I
did authorize a field-expedient on one occasion; we were assembling a
truck tire (either deuce and a half or five ton, can't recall which),
so we removed the inner rear dual and placed the tire to be inflated
on that hub, then locked down the outer (good) tire in place before
inflation of the inner assembly (using the outer tire as protection in
the event the rim popped).

follow ups trimmed...

that's one way...another was to put the tire to be inflated/mounted
with the split rim *facing the ground* prior to inflating...

the approved method was to use an 'inflation cage' to hold the tire
while bringing it up to pressure..

and both the TMs and PM *strongly advocated* using a remote operated
inflator so that no tender pieces of flesh were any where near the
rims when the pressure was coming up.

ck
--
The Ten Commandments display was removed from the Alabama Supreme Court
building, But here was a good reason for the move.*

You can't post "Thou Shalt Not Steal" in a building full of lawyers and
politicians without creating a hostile work environment.

Edna H. on alt.books.m-lackey, 20030930

charles krin wrote:

On Fri, 03 Oct 2003 17:56:05 GMT, "Gord Beaman" )
wrote:

"Brian Sharrock" wrote:

Now, go and check your tire pressures before the next rain shower.

Yep that's right...we used to use "nine times the sq root of the
tire pressure" for the onset of hydroplaning, which is about
right...you ever think about where a steel wheel rolling on a
flat steel surface will hydroplane?...

follow ups trimmed...

I doubt that the rail road rolling stock has much problem with
hydroplaning...

ck

I agree...
--

-Gord.

"charles krin" wrote in message

On Fri, 03 Oct 2003 17:56:05 GMT, "Gord Beaman"
) wrote:
"Brian Sharrock" wrote:

Now, go and check your tire pressures before the next rain shower.

Yep that's right...we used to use "nine times the sq root of the
tire pressure" for the onset of hydroplaning, which is about
right...you ever think about where a steel wheel rolling on a
flat steel surface will hydroplane?...

follow ups trimmed...
I doubt that the rail road rolling stock has much problem with
hydroplaning...

It actually is a serious consideration when the rails are underwater,
as happens frequently out here in the Plains when we get heavy rain.
Engineers have to be aware that it's going to take longer than usual
to come to a stop.

"Duke of URL" macbenahATkdsiDOTnet wrote:

"charles krin" wrote in message

On Fri, 03 Oct 2003 17:56:05 GMT, "Gord Beaman"
) wrote:
"Brian Sharrock" wrote:

Now, go and check your tire pressures before the next rain shower.

Yep that's right...we used to use "nine times the sq root of the
tire pressure" for the onset of hydroplaning, which is about
right...you ever think about where a steel wheel rolling on a
flat steel surface will hydroplane?...

follow ups trimmed...
I doubt that the rail road rolling stock has much problem with
hydroplaning...

It actually is a serious consideration when the rails are underwater,
as happens frequently out here in the Plains when we get heavy rain.
Engineers have to be aware that it's going to take longer than usual
to come to a stop.


Sure it will, but it's from the lubrication of the water reducing
the friction between the wheels and the rail, not hydroplaning.
--

-Gord.

On Fri, 24 Oct 2003 19:04:01 GMT, "Gord Beaman"
) wrote:

"Duke of URL" macbenahATkdsiDOTnet wrote:

"charles krin" wrote in message
m
On Fri, 03 Oct 2003 17:56:05 GMT, "Gord Beaman"
) wrote:
"Brian Sharrock" wrote:

Now, go and check your tire pressures before the next rain shower.

Yep that's right...we used to use "nine times the sq root of the
tire pressure" for the onset of hydroplaning, which is about
right...you ever think about where a steel wheel rolling on a
flat steel surface will hydroplane?...

follow ups trimmed...
I doubt that the rail road rolling stock has much problem with
hydroplaning...

It actually is a serious consideration when the rails are underwater,
as happens frequently out here in the Plains when we get heavy rain.
Engineers have to be aware that it's going to take longer than usual
to come to a stop.


Sure it will, but it's from the lubrication of the water reducing
the friction between the wheels and the rail, not hydroplaning.

There is a difference between lubrication and hydroplaning?
Aren't they different aspects of the same thing?

Peter Skelton

"Peter Skelton" wrote in message
...
On Fri, 24 Oct 2003 19:04:01 GMT, "Gord Beaman"
) wrote:


There is a difference between lubrication and hydroplaning?
Aren't they different aspects of the same thing?


That depends on the type of lubrication.

Hydrodynamic lubrication is essentially the same
thing as aquaplaning, the fluid forms a complete
layer between the surfaces and the wheel
(or bearing) , this is how plain bearings in engines work
when the engine is at speed. The function of the oil
pump is to help maintain this continuous layer of oil.

In the case of boundary layer lubrication there is no
complete layer but instead individual molecules fill
pits and troughs in the bearing surface effectively making
it smoother and more slippery. When you first start
your engine this is the form of lubrication that occurs
until the oil pressure builds up.

Keith

Keith

On Fri, 24 Oct 2003 21:34:21 +0100, "Keith Willshaw"
wrote:


"Peter Skelton" wrote in message
.. .
On Fri, 24 Oct 2003 19:04:01 GMT, "Gord Beaman"
) wrote:


There is a difference between lubrication and hydroplaning?
Aren't they different aspects of the same thing?


That depends on the type of lubrication.

Hydrodynamic lubrication is essentially the same
thing as aquaplaning, the fluid forms a complete
layer between the surfaces and the wheel
(or bearing) , this is how plain bearings in engines work
when the engine is at speed. The function of the oil
pump is to help maintain this continuous layer of oil.

In the case of boundary layer lubrication there is no
complete layer but instead individual molecules fill
pits and troughs in the bearing surface effectively making
it smoother and more slippery. When you first start
your engine this is the form of lubrication that occurs
until the oil pressure builds up.

So in the context we were discussing, it's the same thing.

Peter Skelton

"Peter Skelton" wrote in message
...
On Fri, 24 Oct 2003 21:34:21 +0100, "Keith Willshaw"
wrote:


"Peter Skelton" wrote in message
.. .
On Fri, 24 Oct 2003 19:04:01 GMT, "Gord Beaman"
) wrote:


There is a difference between lubrication and hydroplaning?
Aren't they different aspects of the same thing?


That depends on the type of lubrication.

Hydrodynamic lubrication is essentially the same
thing as aquaplaning, the fluid forms a complete
layer between the surfaces and the wheel
(or bearing) , this is how plain bearings in engines work
when the engine is at speed. The function of the oil
pump is to help maintain this continuous layer of oil.

In the case of boundary layer lubrication there is no
complete layer but instead individual molecules fill
pits and troughs in the bearing surface effectively making
it smoother and more slippery. When you first start
your engine this is the form of lubrication that occurs
until the oil pressure builds up.

So in the context we were discussing, it's the same thing.


Not necessarily, the conditions needed to establish the
hydrodynamic layer are quite complex and are dependent
on pressure and viscosity as well as the bearing load.

With a steel rail and steel wheel the bearing load is high and
water isnt very viscous. The pressure gradient is dependent
mainly on wheel speed since the water effectively forms
a wedge.

Normally you wouldnt expect the result to create enough
pressure to cause a water layer to form. However if you
get wheel slip then it will, a fact known to all engine designers
and suspended solids in the water, especially clay or silt can
cause it too.

Keith

Peter Skelton wrote:

On Fri, 24 Oct 2003 19:04:01 GMT, "Gord Beaman"
) wrote:

"Duke of URL" macbenahATkdsiDOTnet wrote:

"charles krin" wrote in message
om
On Fri, 03 Oct 2003 17:56:05 GMT, "Gord Beaman"
) wrote:
"Brian Sharrock" wrote:

Now, go and check your tire pressures before the next rain shower.

Yep that's right...we used to use "nine times the sq root of the
tire pressure" for the onset of hydroplaning, which is about
right...you ever think about where a steel wheel rolling on a
flat steel surface will hydroplane?...

follow ups trimmed...
I doubt that the rail road rolling stock has much problem with
hydroplaning...

It actually is a serious consideration when the rails are underwater,
as happens frequently out here in the Plains when we get heavy rain.
Engineers have to be aware that it's going to take longer than usual
to come to a stop.


Sure it will, but it's from the lubrication of the water reducing
the friction between the wheels and the rail, not hydroplaning.

There is a difference between lubrication and hydroplaning?
Aren't they different aspects of the same thing?

Peter Skelton

I see that quite a number answered this so I'll just give my gut
reaction to your suggestion Peter. I feel that it isn't
hydroplaning because speed isn't required to start the process.
The wheel will 'slide' on the rail just as easily no matter how
slowly it's being moved, therefore it's not the 'pressure' of the
wedge of fluid 'lifting the wheel' but the molecules of the
lubricant that's filling the dips and valleys between the two
surfaces that's reducing the friction.
--

-Gord.