Water level

[Ray Dunakin]

I've been reading some back issues of GR lately, and getting a lot of great info from them. An article in the August 2003 issue about making and using a water level has been especially helpful. With the difficult terrain on my layout, I was having trouble determining the correct elevation for the roadbed at each end of the layout. A water level has solved that problem!

What's a water level? It's a very clever, simple device made from a length of clear plastic tubing. Attach the end of the tube to a wooden stake, so that when the stake is in the ground, the end of the tube runs vertically up the side of the stake. Do the same at the other end of the tube. You can glue a cheap yardstick to the stake, or just use a tape measure to mark inches directly on the stake.

Put one stake at one of the layout, and the other stake at another point on the layout. Fill the tube with water. The water at each end of the tube will always be level. Measuring how many inches difference there is between the position of the water at each stake will tell you how much higher or lower the second stake is from the first one.

[grandpopswalt]

I've been using a laser level to do terrain mapping. I think it's pretty accurate but I haven't thought of a way to check it's accuracy. I haven't made a water level to check it (then why would I need a laser, right?) Anyone have a method I could use?

Walt

[whiterab]

A quick way to check the accuracy of a level is to shoot it both ways. Set up two stakes as far apart as your laser will reach. Put a mark on the first stake and set your laser at that mark. Shoot a level to the second stake and mark the point on the second stake.

Now move your level to the second stake and repeat the proceedure setting the level at the mark you made on the second stake. If your level is okay, the first mark on the first stake should match up with the laser dot from the second sighting.

Found out the hard way that sometimes lasers don't match the bubble.

[kstrong]

The best way to check the accuracy of a laser level that I've found is to mount it on a tripod in the middle of the yard, and pan it back and forth along the back of your house. Whether you've got siding or brick, there's generally a long horizontal line on the house against which you can measure the accuracy of the leveling. Once you've got it leveled, DO NOT MOVE THE TRIPOD. You only want to pan the level around.

A few tips: Use a good, sturdy tripod. The flimsy one you got for $20 at Wally-World isn't really going to work too well. If you have a friend who has professional photography equipment, ask them if they have a tripod you can borrow.

Some tripods have bubble levels built in. They're good as a starting reference, but not 100% accurate. Also, they'll tell you when the tripod is sitting level, but do not indicate how level the mounting surface of the head itself is. You need both to be level. When the tripod itself is level, the axis around which the head revolves will be perfectly vertical. The mounting surface of the head (onto which the level will be mounted) needs to be level, so that you get consistent readings no matter how far the target is from the level. (If it's not level, your laser will essentially draw a cone; the farther away the target, the higher or lower the indicator.)

When shooting the targets, rotate the level by rotating the head of the tripod, not just the level on top of the tripod. This eliminates any chance for inconsistencies stemming from irregularities on the mounting surface.

DO NOT BUMP THE TRIPOD. It's hard, especially if the legs stick out unusually far, but if you bump it, you'll probably throw off the accuracy.

Having said all that, I'll take a laser level over a water level any day of the week. I've used both extensively, and the water level is far more difficult to get consistent results from. There are too many variables; surface tension, spillage, and the inherent inaccuracy that comes from constantly moving the level from one point to the next (unless you've got a very long hose).

Surveying and grading your railroad with a laser level is a breeze compared to using a water level. Beginning in the June Garden Railways, I have a series chronicling the construction of my railroad. In virtually every step, the laser level is involved to some extent, from the initial yard survey to setting the general profile of the raised gardens to setting the sub-roadbed. It's an absolutely invaluable tool, and they're so inexpensive now that there's no excuse for one not to be in every garden railroader's toolbox.

Later,

K

[Anonymous]

In addition, if 1/2 of the hose for the water level is in the shade and the other half is in the sun you will not get accurate results due to expansion from the heated water in the other half of the hose. I had a water level and found using a string and line level to be fairly accurate.

dan

[ttrigg]

I have been using water levels for over 40 years. When properly used they are extremely accurate. Even when one end is laying on ice and the other end is in hot sun light, the deviation will be less than one thousandth of an inch. More than accurate enough for use in the GRR. Use a clear tube of ¼ or 3/8 inch clear tube. Larger tubing becomes cumbersome to work with, especially when working at distances of 50 or more feet. Before putting the water in the tube mix some red food color with the water (yellow is hard to see, green and blue blend into the garden colors too easy.) With the ends of the tubing attached to yard sticks subtract one reading from the other and you will have your elevation change. Water levels are extremely useful when digging/building a water way to ensure proper water flow over rapids/falls.