DIY surveying , as in land levels?

[Adam Aglionby]

Looking for a basic method of mapping out heights over an area just over 2 acres.

Ex railway goods yard that has been , er , left to nature for a few years, as it was originally cut into side of a hill have one access track down a l oading bank and a yard at what was rail level and yard area that served th e goods shed with access shared with Network Rail.

Track was lifted probably late 70`s no trace is visble of ballast through o vergrowth.

What exists of original plans from 1868, shows a possible slight incline do wn towards the goods shed.

NR has used some of the intervening years to dump excess ballst and old con crete sleepers down one end, line and station adjacent are still live.

Not looking to create plans suitable for planning, it`s development now inv olves encouraging nature and restoring the goods shed, but being able to ge t some idea of heights in section would help cure some of the sites current drainage problems.

Any advice?

Thanks

[Bill Wright]

Traditionally you'd use a dumpy level or similar. Very easy and straightforward. Basically you establish an arbitrary datum point on something fixed like a brick building. You bang sticks or rods into the ground at strategic intervals and use the dumpy to transfer the datum level to the sticks. Mark with white or yellow tape on the sticks. Then move the dumpy down the site and check the levels marked are in agreement, then swivel it round and establish further levels on more sticks. And so on. Finally measure down from the datum levels to establish ground level at that point. You need an accurate plan to mark the poles and levels on. You might have to make an adjustment to the datum level if the site slopes a lot. You just establish a new one a fixed distance above or below the first one, then allow for the difference when you transfer levels to the plan.

It's a good idea to work in a circle so you can do a double check against the original datum.

Bill

[The Natural Philosopher]

hire a laser theodolite

set it up and use a stick to measure ground below horiz beam. easy peasy.

[Tim Watts]

Option 1:

Hire a Leica TotalStation - weekend hire can be cheap as few professionals want it then. I did this once - made me scared handling and storing £7-8000 worth of uninsured kit!

Spend a week reading the downloadable instructions first!

Pros: Dead easy and quick to get an x,y,z survey.

Cons: Costs a bit and you'll need a week to read the instructions!

Option 2:

Good excuse to buy a super bright green laser level.

Set up near the end of the day and depending on how far the beam reaches (green should be better than red) walk around with a depth stick rule measuring ground to line. Estimating your x,y position is a little harder - if you have a way to rough the area into a basic grid, work to that.

I sized up a big slope in my garden like this.

Pros:

Good excuse to buy a fine green self levelling laser.

Cons:

Harder work and less accurate (well the x,y bit - z accuracy will be good).

[John Rumm]

You could make a plane table fairly easily. I made one for someone once using a tripod from a laser level (handy since it had the levels already built in), and fixed a drawing board to it. Then made an alidade from an old air pistol red dot "holographic" sight.

[Tim Watts]

Called a totalstation - just so this ties to my post :)

[news]

You could download the LIDAR data for the area if you have a viewer for it

AJH

[Alan Dawes]

Is there a college near by? If so why not offer access to the site for their students learning surveying. My local college regularly uses the local park for this because they don't have access to any other suitable area.

Alan

[harry]

, as it was originally cut into side of a hill have one access track down a loading bank and a yard at what was rail level and yard area that served the goods shed with access shared with Network Rail.

down towards the goods shed.

oncrete sleepers down one end, line and station adjacent are still live.

nvolves encouraging nature and restoring the goods shed, but being able to get some idea of heights in section would help cure some of the sites curre nt drainage problems.

If you don't need precision and ordinary laser lever on a spirit level will do. (£5)? Set it up by day and then use at night when the "dot" can be detected at te n times plus the quoted normal range.

Some goods yards had a designed gradient so that uncoupled wagons would rol l about under gravity without needing a shunter loco.

[harry]

, as it was originally cut into side of a hill have one access track down a loading bank and a yard at what was rail level and yard area that served the goods shed with access shared with Network Rail.

down towards the goods shed.

oncrete sleepers down one end, line and station adjacent are still live.

nvolves encouraging nature and restoring the goods shed, but being able to get some idea of heights in section would help cure some of the sites curre nt drainage problems.

The other way is to make up a water level using a long hose pipe. This gives spot on accuracy over long distances. Make sure there are no air bubbles in the hose.

Or you can buy one.

[Harry Bloomfield]

When I first moved into this property, with its large back garden and wondering what I might be able to do with it, I did an X, Y approximate survey. A ten foot horizontal pole, with a table at each end. Sight various points from each end of the pole, to find the angle to the pole then list the points and angles.

From that I was able to manually transfer a scaled 10 foot baseline onto a sheet of A3 and project those angle on the sheet, to recreate the points on my sheet. I still have that drawing filed away and it proved to be fairly accurate.

[Johnny B Good]

====snip====

There's an even simpler variation on this method (assuming we're not dealing with acre sized plots). Replace the U tube with 50 metres or whatever length of garden hose is required, terminated with clear tube (glass or plastic or short length of clear plastic hose) to act as sight glassess (alternatively, use transparent plastic hose in place of ordinary garden hose if you can get hold of the required length at an economic price).

You can avoid fabricating a wooden cross and just use stakes strategically placed very firmly into the ground and promote one of them as your datum reference by which to mark the datum level onto the rest of the stakes by simply dragging the free end of the hose from stake to stake instructing your helper to adjust the height of the free end against each post as you hold the 'fixed end' against the datum reference post to align the meniscus of the water against the reference mark.

Once your helper has set the level at his end so that the meniscus lines up with the reference, you can instruct him to mark the post against the meniscus and it's job done to within a millimetre without introducing any guesswork involved in using a tube as a 'gun sight' to extend the short baseline of your water level out to each remote stake.