Evolution of road graders

A road grader is a fascinating piece of construction equipment. Modern ones like the Caterpillar motor graders shown above have enhanced GPS-based controls on their blades (antennas indicated by arrows). They don’t need surveyors and stakes to grade land to a desired contour. How did graders evolve?  

On Tuesday, September 3rd we were driving south in Oregon on U.S. Route 97 and drove past the Collier Logging Museum 30 miles north of Klamath Falls. On Thursday September 5th we stopped and visited that lovely 146-acre museum. It has equipment from three eras: horse and oxen (1860 – 1900), steam (1890 – 1920), and internal combustion (1920 – today). There also is a ‘village’ of historic log cabins.

In displays on the horse and era there was a sign and an Adams Leaning Wheel grader. At the Historic Indianapolis.com web site I found more on Adams graders in an article by Lisa Lorentz on August 31, 2014 titled Sunday Adverts: Don’t Read This. The South African KHPlant web site has more Historic Motor Grader Pictures showing the evolution.

I looked on the Library of Congress web site and found two pictures showing road grading in Alaska, one from 1916 showing another tractor towed grader, and one from 1942 showing a motor grader working on the Alaska-Canada highway.    

Blasting rocks

Yesterday shortly after 4:00 PM our house shook from a nearby explosion. When I looked out a back window I saw a cloud of yellowish smoke rising in the southeast. Close to where I live contractors are digging trenches to bury plastic pipes below the frost line for the Locale subdivision (formerly called Syringa Valley). Work is proceeding east of Cole Road and south of Latigo Drive.

As is shown above, south of Lake Hazel Road there are Ingersoll Rand and Atlas Copco percussion drills (presumably owned by Superior Blasting) working together making holes in the ground prior to blasting for removing those stubborn rocks.

Further east there also is a large stockpile of plastic pipe.

An excavator and an enormous Trencor trencher also are working north of Lake Hazel Road. (I blogged about the trencher on March 30, 2016 in a post titled Explaining something by comparison with the familiar). But some of the ground is apparently rockier than the excavators or trencher can handle.

How would you line the sloping walls of a large irrigation canal with concrete?

Near where I live there is a large road and intersection construction project in progress. The intersection of Cole Road and Lake Hazel Road is being redone, and Lake Hazel Road will be extended eastward, and cross over the ~45 foot wide, century old, New York Canal via a bridge (which has not been built yet). The New York Canal takes Boise Project water from the Boise River to Lake Lowell in Nampa. It runs for ~40 miles. A few days ago a crew from the Concrete Placing Co. was also finishing lining the canal walls upstream and beneath the bridge. Lining the canal is less than 10% of the road project.

Lining the flat canal bottom is like a bigger version of putting in a sidewalk, driveway, or patio. You likely are familiar with that. The area is dug out, and the edges of the patio are walled with forms to contain the concrete. Then concrete is brought to the site by a mixer transport truck, and delivered via an attached chute (or with wheelbarrows). As is shown above, two guys use a 2x4 board as a screed to strike off the top of the concrete level with the tops of the forms. Then the top can be finished further with a float and edger.  

If you wanted to demonstrate ‘striking off’ to a small audience you might use a 9” square cake pan as the form, a 12” long ruler as the screed, and a granular solid like kitty litter to represent concrete. Pictures or videos work better for a larger audience.

What about the sides of the canal? As shown above (viewed from one bank looking southeast) the sides were divided into panels ~12 feet wide. Half of them were poured using forms, and then the other half were filled in. You can see the welded steel wire reinforcement mesh laid where the new concrete will be placed. A chute from the concrete truck delivers a very stiff mix. Then a Deere tracked excavator uses a pair of ropes to pull a metal screed rod up the wall starting from the canal bottom. That rod is guided by two men using the panels already on both sides to support the ends. You also can see a concrete abutment for the new bridge at the very right.

The image of screeding came from Wikimedia Commons.

Explaining something by comparison with the familiar

South of Boise and east of Cole Road, on the sagebrush that will become the Syringa Valley subdivision, I saw an enormous piece of construction equipment that I’d never seen before. It was a Trencor 1660 HDE chain trencher. Just imagine a Ditch Witch on steroids. Did that help? Probably not, unless you’ve already seen one cutting trenches for installing sprinkler pipe or TV cable.

But most people are familiar with chain saws, like the one shown above. Imagine a longer, wider chain saw mounted on a vehicle with wheels or tracks underneath, like the Ditch Witch R300 shown below. That’s a chain trencher.

Wikimedia Commons has a category with 32 images of them. The accompanying text says:

“A chain trencher cuts with a digging chain that is driven around a rounded metal frame (formerly sometimes a rotating wheel at the end of a boom). This type of trencher can cut ground that is too hard to cut with a bucket-type excavator. The angle of the boom can be adjusted to control the depth of the cut. To cut a trench, the boom is held at a fixed angle while the machine creeps slowly. Chain trenchers are used for narrow to wide trenches, especially in rural areas. The excavated material can be removed by conveyor belt to either side of the trench.”

Here’s what that Trencor 1660 HDE looks like. I found a 2000 brochure from Trencor here. The engine is a 750 hp turbocharged Caterpillar V-12 with two 520 gallon fuel tanks. Crawler tracks underneath (from a Caterpillar D8 bulldozer) are 19-1/2 feet long, and the rear overhang is another 12-1/2 feet. It’s 13 feet wide, 12 feet high, and weighs over 107 tons.   

And here is a brief YouTube video of one at work:

Images of a chain saw and a Ditch Witch R300 both came from Wikimedia Commons.

A really big bench for a morning break

This morning I had to chuckle when I saw saw four construction workers taking a break to discuss what would happen next on a nearly complete road project.

Their truck wasn’t parked nearby, so they improvised by using the 10-foot wide bucket of a Caterpillar wheel loader for seating. By the way, that CAT 966H is described as only a Medium Wheel Loader.