Railway Sleeprs

Andy wrote:

Derek Broughton wrote:

What makes you think that? It's not true. The lateral force is exactly
how these new self-supporting above-ground swimming pools get their
stability. However, the greatest lateral force is at the bottom of that
above-ground section, so maybe it'll work.

But the lateral force works in all directions at the same time, which is
why the swimming pools are stable. The lateral force of water at 1 foot
deep is 0.433 psi. Assuming the frame and joints are secure and can cope
with the low psi then the force in one direction is canceled by the same
force in the opposite direction.

That's the big assumption though - the joints are the least stable part,
especially when working with things like railway ties.

Here I start delving into math I haven't used in 30 years... Assuming a
railway tie is 8' x 8", and you want 2' above-ground (3 ties), then (I
think) the lateral force on the top tie is going to be somewhere around 12
pounds. The force on the one below that is higher, but it's also braced by
the weight of the tie above it. I guess 12 pounds isn't nearly enough to
move a tie, except at glacial speed (and if it's a shorter tie, the force
is correspondingly less), but I still think you want to be really careful
about those joints.
--
derek

Derek Broughton wrote:

the weight of the tie above it. I guess 12 pounds isn't nearly enough to
move a tie, except at glacial speed (and if it's a shorter tie, the force

No, especically as the ligthest sleepers weigh in at around 120 pounds
and can be more than double that. The lateral force would need to be
even greater to move when friction is taken into consideration. Which
comes back to where I started, the weight of the sleepers alone is
sufficient to make it a non-issue.

--
Andy

On Wed, 03 Aug 2005 19:05:55 +0100, Andy wrote:

Derek Broughton wrote:

the weight of the tie above it. I guess 12 pounds isn't nearly enough to
move a tie, except at glacial speed (and if it's a shorter tie, the force

No, especically as the ligthest sleepers weigh in at around 120 pounds
and can be more than double that. The lateral force would need to be
even greater to move when friction is taken into consideration. Which
comes back to where I started, the weight of the sleepers alone is
sufficient to make it a non-issue.

What about the effect of the natural vibration of the Earth? Even though it
is minimal, except in California , it is a constant force/movement that
has to be considered. Granted the surface friction would be higher
initially but over time wouldn't that decrease due to wood deterioration
and said vibration/movement?
--
Disciple - Team Z
Thus says the Lord God; "Woe to the foolish prophets, who follow their own
spirit and have seen nothing." Ez. 13:3

Thanks for all the advice chaps - It looks like although opinions are
divided it's worth a go, so..... I'll build the pond & let you know the
results...... I hadn't taken into account Glacial movement or earth
friction - I was more worried about the (hopefully) large Mirrors & Leathers
being strong enough to nudge the sides !!!!

Thanks again

David

"David Sim" wrote in message
...
Morning all

I'm building a part raised pond - 9' x 6' - hole is dug to 4' & I'm
planning on raising the dges by another 20" or so using railway sleepers.
I think new ones will be better, cleaner & easier to use, but does anyone
have any thoughts on securing them to the ground.

Will a frame of sleepers secured with heavy duty brackets be strong enough
to hold the additional 20" of water?

Cheers

Just to throw some numbers on this discussion, using the 8" x 8" x 8'
dimensions for a sleeeper, at the 20" depth there will be 3/4 psi of
STATIC pressure on the side of the sleeper. The AVERAGE pressure on
the bottom sleeper will be 5/8 psi, I'm going to round off to .6 psi.
The TOTAL pressure on the side of the sleeper will be .6 x 8" x 96" or
460 lbs!!! This is NOT a trivial pressure as others have claimed.
Use good, sturdy brackets, and some buttressing wouldn't hurt.

I see two potential problems: There is going to be a lot of water
around, and moisture will collect between the sleepers. Yes, they are
treated, but if any organisms grow in that water you COULD have
problems. In a few years you might have something which closely
resembles two greased pigs stacked upon one another.

The other is more mundane, and may not apply. Are you in an area
where freezing occurs?

PlainBill

On Wed, 3 Aug 2005 21:26:42 +0100, "David Sim"
wrote:

Thanks for all the advice chaps - It looks like although opinions are
divided it's worth a go, so..... I'll build the pond & let you know the
results...... I hadn't taken into account Glacial movement or earth
friction - I was more worried about the (hopefully) large Mirrors & Leathers
being strong enough to nudge the sides !!!!

Thanks again

David

"David Sim" wrote in message
...
Morning all

I'm building a part raised pond - 9' x 6' - hole is dug to 4' & I'm
planning on raising the dges by another 20" or so using railway sleepers.
I think new ones will be better, cleaner & easier to use, but does anyone
have any thoughts on securing them to the ground.

Will a frame of sleepers secured with heavy duty brackets be strong enough
to hold the additional 20" of water?

Cheers

Not serious freezing - central southern England - minus 2 - 3 degrees

"PlainBill" wrote in message
news
Just to throw some numbers on this discussion, using the 8" x 8" x 8'
dimensions for a sleeeper, at the 20" depth there will be 3/4 psi of
STATIC pressure on the side of the sleeper. The AVERAGE pressure on
the bottom sleeper will be 5/8 psi, I'm going to round off to .6 psi.
The TOTAL pressure on the side of the sleeper will be .6 x 8" x 96" or
460 lbs!!! This is NOT a trivial pressure as others have claimed.
Use good, sturdy brackets, and some buttressing wouldn't hurt.

I see two potential problems: There is going to be a lot of water
around, and moisture will collect between the sleepers. Yes, they are
treated, but if any organisms grow in that water you COULD have
problems. In a few years you might have something which closely
resembles two greased pigs stacked upon one another.

The other is more mundane, and may not apply. Are you in an area
where freezing occurs?

PlainBill

On Wed, 3 Aug 2005 21:26:42 +0100, "David Sim"
wrote:

Thanks for all the advice chaps - It looks like although opinions are
divided it's worth a go, so..... I'll build the pond & let you know the
results...... I hadn't taken into account Glacial movement or earth
friction - I was more worried about the (hopefully) large Mirrors &
Leathers
being strong enough to nudge the sides !!!!

Thanks again

David

"David Sim" wrote in message
...
Morning all

I'm building a part raised pond - 9' x 6' - hole is dug to 4' & I'm
planning on raising the dges by another 20" or so using railway
sleepers.
I think new ones will be better, cleaner & easier to use, but does
anyone
have any thoughts on securing them to the ground.

Will a frame of sleepers secured with heavy duty brackets be strong
enough
to hold the additional 20" of water?

Cheers