Jack Plant


1921 photo of the jack plant above Elsmere Canyon. It is from "Oil-Field Practice" by Dorsey Hager, McGraw-Hill Book Co., New York, p 118. It was found by Jeff Brantly.


This is a jack plant (also called a pump house or jack house) on a terrace cut into the mountains on the high area just above, and south of, Elsmere Canyon. Although not physically in Elsmere Canyon, it is part of the Elsmere Canyon Oil Field. The plant is in pretty bad shape, having been burned, cut in pieces, and vandalized over the years (and still being vandalized today). There is also a jackline cradle on top of a high ridge overlooking Elsmere Canyon nearby to the north.

The main machinery at the jack plant is a central power unit (also called an Allen power unit after the original patent holder or just a "power"). The Elsmere power rotated one eccentric wheel (wheel with the axle not in the center, although the top eccentric was not shaped in an typical oval pattern). As the eccentric rotated, it alternately pushed and pulled steel cables (called jacklines, shacklelines, or jerk-lines) attached to remote pump jacks at the wells. If necessary (when flexible cables were used as in this case), the remote pump would use a weight to provide for the return stroke, or downstroke, of the pump while the power would provide the upstroke. The downstroke could also be caused by the weight of the column of oil on the plunger of the pump and the weight of the sucker rods with maybe some assistance by weights. The jackline had to be kept as taut as possible. This setup could power pumps over a great distance. This power was probably always powered by a gas engine.

In the early days of the oil industry, wells were pumped individually. This wasted both labor and power - each well requiring a man and some sort of power (usually steam). However, a jack plant could operate a group of wells with practically the same labor and power as a single well. Whether a group of wells could use this method depended on many factors including location, topography, quantity of oil, type of oil, gas pressure, amount of sand, amount of water, depth of well, and many other factors. A jack plant would allow wells that would otherwise be abandoned to be pumped profitably for many years. Prutzman (1904 - see sources) reported that "most of the wells in all parts of the Newhall Field are pumped by means of the jack" (p. 29). In 1934, Walling reported 7 wells still in operation in this area of the Elsmere oil field. However, he did not mention anything about jacklines. In 1940, Waldo Ford (UCLA thesis) mentions that 7 well pumps were being powered by jacklines. Oakeshott (1958) reported that in 1942, 6 wells were in operation. This jack plant dates to after 1907 (the year E.A. and D.L. Clampitt bought the Santa Ana and Alpine Oil Company wells) but before 1921 (the year of the above photo). This would physically place it somewhat in the middle of the 7 (3 Santa Ana wells, 3 Alpine wells, and 1 Clampitt well) wells in the area.

The jackline cradle held the rods or cables from the plant to the pumps on the south side of Elsmere Canyon. Based on the condition of the existing wells, it looks to me like three wells on the south face were pumped using jacklines. These would be Clampitt 8 (the original Santa Ana 1), Clampitt 9 (Santa Ana 2), and Clampitt 10 (Santa Ana 3). On the other side of the ridge, very near the plant (and not needing the cradle) was Clampitt 12. Its pump also must have been powered with a jackline. As to other wells that were on jacklines, I really can't tell. There are no more visible well heads in the area. The above 1921 photo shows cables extending out over the road where the picture was taken. These could have been either for other wells (the Alpine wells) or for counterweights.

Here part of an 1985 Division of Oil, Gas, and Geothermal Resources (DOGGR) video showing a jackplant in action (mp4). The jackplant was located in the Santa Paula Oil Field in Ventura County, California. (I'm assuming that it no longer runs.)

The following photos were taken in May and June of 2007. Unfortunately, by 2017, the jackplant has been badly vandalized. For example, the old engine at the plant does not have a flywheel or shaft anymore. The MRCA, the custodians of Elsmere Canyon, did not deem it necessary to surround the site with a fence.


This well (Clampitt 10 - originally Santa Ana 3) is below the jackline cradle in the distance. A jackline probably powered the pump that once was connected here.


This well's (Clampitt 9 - originally Santa Ana 2) pump was probably also powered by a jackline from the jackline plant.


At the jackline cradle. My pack is under the cradle. It is about 4-feet wide and 10-feet high. There is another set of poles that may have been an earlier cradle that looks like it was not strong enough to hold the cables from the jackline plant and had to be replaced by the current cradle.


View of the jack plant from the cradle. The site is about 100 yards away.


Closer view.


Another view.


Jack plant site. The dimensions of the site are about 22-feet wide by 56-feet long. There is an old gas engine in the foreground and a tank in the middle. In the background are an eccentric wheel shaft, a geared shaft, a newer gas engine block, six small concrete squares, and one concrete rectangle.


Closer view.


Let's try to put jackline power plant together (see the Lockwood Power diagram at the bottom of this page). My hammer is resting at the top of the eccentric wheel. The maximum diameter of the wheel is about 2-ft 3-in and the minimum diameter is about 1-ft 8-in. The shaft is about 7-ft long with a 3 1/2-in top diameter and a 4 1/2-in bottom diameter. It would be placed vertical. The top would have a metal round disk that could freely rotate (see next photo). The jacklines would be attached to it. As the eccentric wheel rotated, the jacklines would be pulled back and forth (and side to side) causing the pumps at the well heads to go up and down. Because the round disk was free to rotate, the relative positions of the jack lines would not change so the lines would never cross over each other. The gear at the bottom of the shaft has been cut off.


This is a wheel with an eccentric disk mounted on top that would have been on top of the previous eccentric wheel. This is actually from the power in Pico Canyon near CSO 4, which is very similar to this power. Note all the positions around the outside of the disk where jacklines would have been attached to.


Close-up view of the shaft support structure. Note the diagonal angle of the metal where a large piece of wood would have been connected.


Another close-up view of the shaft support structure. Note the metal rod attached to it. Besides a wooden structure, metal rods were used to hold the shaft upright.


Here are some of the rods that were used to hold up the structure.


Another view of shaft with eccentric wheel.


This is the piece that was cut off the bottom of the eccentric wheel shaft from the above pictures. It has been shoved over the side and is now resting on the road below the jack plant. Its axle would have been vertical placing the wheel horizontal with the geared side down. The shaft height is 3-ft 4-in. The diameter of the gear wheel is 4-ft. The top shaft has a 4 1/2-in diameter matching the bottom diameter of the eccentric wheel shaft, with which it was once attached. The last 4-inches of the bottom of the shaft has a diameter of 3-in. This section would have been placed in some base and allowed to freely rotate. Except for one piece of burnt wood, the base and all structure holding up the shaft is gone. When the jack plant was operating, the main shaft with the eccentric wheel and this geared wheel was 10-feet tall. This was a tall, very heavy structure that would need a lot of support.


View of geared side of wheel.


View of 3-in diameter 4-in long bottom section. This would have been placed in some base and allowed to freely rotate.


Here is the wheel's new position as of February of 2008. Some person or persons pushed it over the side of the hill and rolled down to here.


Here is the shaft with the gear that rotated the eccentric wheel. It would have been mounted horizontally, like it is now. The shaft is 3 1/2-in in diameter and is 6-ft long. On the opposite side of the gear, a pulley would have been mounted. A belt would stretch between this pulley and the one on the old engine in the distance (a distance of about 33 feet). As the belt rotated the pulley, the gear rotated the eccentric wheel shaft, pulling and pushing the jack lines. When it was mounted, it looks like the larger two-disc circular structure on the middle of the shaft fit in the concrete structure in the upper left of the picture.


Close-up view of gear from above shaft.


This pulley was mounted on the shaft on the opposite side of the gear. The belt from the engine would have been looped around it. It is not on the jack plant site.


Here on the site is where the eccentric wheel structure was. My pack sits on the spot where the 10-ft shaft was vertically mounted. The site has 4 concrete square bases on the far, west, side (two 4 1/2-ft squares on the outside and two 2 1/2-ft squares on the inside) and three concrete bases on the closer, east, side (two 2 1/2-ft squares and one 2 1/2x5 1/2-ft rectangle). The distance between these sides is about 8 1/2-ft. The wider distance (from left to right in the picture) is about 19-ft (between inner part of outside concrete squares). It looks like it could support a large structure that was necessary to contain the 10-ft high eccentric wheel shaft and gears.


Close-up of one of the 4 1/2-ft squares that was part of the structure.


Large piece of burnt wood, probably part of the jack plant wooden support structure.


On the other side of the site is the older gas engine. The one large flywheel is 4 1/2-ft in diameter. A second similarly sized flywheel on the other side is missing. The wider, smaller pulley (10 1/2-in in diameter) would be for the belt that would rotate the pulley on the geared shaft in the distance. The belt would have had to stretch about 33-feet. The crankshaft between the two flywheels would have one piston attached to it. It appears that this engine used to have more pieces attached to it.


Another view of engine showing the crankshaft.


View looking in the opposite direction of the cradle showing pipes that probably held up a jackline probably for counterweights. Straight out in the distance is a flat area where 1979's Margaret Bath 1 was located. The Alpine wells would be to the right of the photo at the bottom of the slope.


Close-up of 4-cylinder gas engine block. It probably replaced the original engine and powered the jack plant.


Closer view. The pen is resting on what appears to be the serial number - "SP 3717 HA8". In the middle it says "487 DC". On the right it says "6-18-36" (upside down). On the other side of the block, it says "Firing Order 1 3 4 2". I assume the engine was finished on 6-18-1936 and probably mounted here shortly after that to replace the engine on the south side of the site.


Side view of 4-cylinder gas engine block.


This tank was removed in late 2011. I don't know what it was used for. It would not have been needed for the original jack plant. The dump EIR claims a boiler was originally here, but based on the above 1921 photo of the plant, I doubt it. There is no pipe fixture on the tank, so any pipes into the tank would have to enter over the top. The tank is 5 1/2-ft tall with a 6-ft diameter.


This pile of dried up oil is next to the road just below the jack plant. It actually was the inside of an old tank. You can see the outlet pipe sticking out on the other side and you can also see the tank hoops nearby. The hoops would have been used with a wooden tank.


This metal cable with a hook on the end is located in a gulley on the south side of Elsmere Canyon. It must have been a jackline.


These jacklines were spliced together using a narrow pipe with rivets through it.


The supporting structures for jacklines were varied depending on what the jackline needed to do. Here are some examples from "Surface Machinery and Methods for Oil-Well Pumping" by H.C. George (1925).


Here are what appear to be two support structures (right two red circles) for a jackline to the well (Clampitt 10 - originally Santa Ana 3) in the lower left red circle. There is also another similar (but fallen down) structure on the same ridge as the other support structures just across the gulley from the well out of the picture. These are below the jackline cradle.


Here is a "grasshopper" style pump jack. It may, or may not, have been used in Elsmere Canyon, but it shows how a horizontal jackline motion can be transferred to a vertical motion to operate a pump. The jackline (A) from the power, pulls and pushes the V jack knee (B). A pitman (D) is attached between the V jack knee and the walking beam (C). The pitman raises and lowers the pump rod (E).


This jack plant setup is very similar to the one here above Elsmere Canyon. (From Watts, 1897)


Here is another power photo from a different jack plant


Power diagram from "Oil-Field Practice" by Dorsey Hager. This is very similar to the Elsmere power except that there was only one eccentric at the top.


The power in the upper right hand corner of this picture is very similar (but shorter) to the one that we have just been looking at. It has one disk mounted on the eccentric wheel. All the jacklines are connected to the disk.

Drawing credit to: Historic American Engineering Record (HAER), National Park Service, Eric S. Elmer, 1997, Haer PA-437


Drawing credit to: Historic American Engineering Record (HAER), National Park Service, Eric S. Elmer, Kara Hurst, 1997, Haer PA-436


Jack plant site on 4/30/2017. The flywheel and shaft that were on the old engine in the background are gone. I don't know whether they were stolen or pushed over the side of the hill. The tank was removed in 2011 by the DOGGR when they capped some of the wells here. Everything else has been moved around, not to mention the overgrown brush.