1911 - 1941: The Union Pacific Coal Company's No. 4 mine at Hanna, Wyoming
Page by Bob Leathers
The Union Pacific Coal Company's Hanna No. 4 Mine opened mine development on April 4, 1911 and opened coal production in 1912. The No.1 Mine was partly built from salvaged parts of the No. 1 Mine after the March 28, 1908 explosion. The mine produced only 29,583 tons of coal in its first year. The mine closed production at the end of 1941 when the mining operations were moved out of Hanna to the new 4A Mine facility north of town. The mine operated in Hanna for 30 years and produced 10,226,125 tons of coal with a peak work force of 331workers. The Hanna Basin Mines (Hanna, Elmo, Sampo, Carbon, Dana, and Wagon mines) experienced a total of 373 miner deaths. The No. 4 Mine in Hanna was responsible for 24 of the 373 deaths.
- More at: 24 men killed in the No. 4 Mine.
Hanna No. 4 and 4A Mines
This mine, which is now the principal operation in Hanna, was opened in April 1911, on the No. 2 Seam, north across a large fault from the No. 2 Mine workings, and was intended to replace the No. 2 Mine as it became worked out and abandoned. The mine was opened by driving a series of slopes down the west rim of the basin for a distance of 4,300 feet, at which point the cover was over 1,400 feet. Working a thick seam of coal at this depth with the mining conditions found in this locality became a very hazardous operation, and the slopes were not developed farther down the pitch. From the main slopes strike entries were turned off each side at about 800-foot intervals, and from these strike entries panel planes or slopes are so located and developed that strike rooms driven from the same are enabled to work out the coal areas between a series of approximately parallel faults. At times these strike rooms were 1,000 feet long to reach the fault areas. Each one of these blocks constituted a miniature mine in itself. Some of the faults encountered in this mine displace the coal vertically as much as 300 feet, which makes the driving of long, expensive rock tunnels on each of the various strike entry haulage ways necessary to connect up the several blocks of coal to be mined and delivered to the preparation plant at the surface. The main haulage way at this time extends from the main hoisting slope to a distance of about two miles to what is known as the North Slope, from which point a large area is under development, and this is the present producing area for the mine. The haulage for this coal is becoming increasingly expensive, and with the outside facilities rapidly becoming obsolete, it is planned to construct a new entrance to this mine about three miles to the north, and to install an entire new plant with modern equipment, during 1942. It was in this mine that the first mechanical equipment for loading coal was installed in a mine of The Union Pacific Coal Company, and this was likewise in the first installation west of the Mississippi River. Small Thew dirt-handling shovels were installed in 1916, as no mechanical coal-loading equipment had been perfected and placed on the market at that time. These shovels required a minimum height of 16 feet in which to operate, and this did not constitute much of a problem in a seam of coal 20 or more feet in height. The next development was the installation of 4-BU Joy loading machines to speed up pioneer development work, which was driven from 8 to 10 feet high, to be followed later with the Thew machines, which loaded out the remaining 10 to 15 feet of top coal. The Thew machines are now obsolete, and all coal is now being loaded out in two benches by the use of modern Joy coal-loading machines. This mine is now 100 per cent mechanized. The mine is gaseous, but is well ventilated, and rock dusted throughout. The general Safety standards of The Union Pacific Coal Company are being maintained at this mine, adding greatly to the safety of operation. (UPCCEM, Nov. 1940)
Union Pacific Coal Company's No. 4 Mine and Town of Hanna
The Union Pacific Coal Company's No. 4 mine lies directly under the town of Hanna. The Pillars in the mine were not drawn in order to keep the town from settling into the mine.
Hanna No. 4 Main Pumping Equipment
By E.R. Henningsen, Chief Electrician, Hanna, Wyo.
Recently there has been installed at Hanna No. 4 Mine a complete new main pumping equipment, consisting of two Allis Chalmers six stage 4x5 200 H. P. centrifugal pumps, each having a capacity of 450 gallons per minute against a 725-foot head. The first of these pumps is located at Fifth North Entry, and the other about midway from the Fifth North Entry to the top. In order to secure these locations, which were deemed essential to attain equal and proper heads, it was necessary to make entirely new sump and pump rooms.
The lower sump was made by driving a place about twenty feet wide and three hundred feet long, then raising three crosscuts to a place driven parallel to the first and some thirty feet above it which acts as a settling basin before the water reaches the main part of the sump. A concrete dam was then placed across the lower place just outside the first crosscut, making the sump and the portion outside the dam forming the pump room, which was again closed off from the rest of the mine by a set of steel doors set in a concrete stopping. This sump has a capacity of around one half million gallons, or is sufficient to hold about five days water with no pumping. This location gives the pump static and dynamic heads of 255 and 325 pounds respectively. The top sump was made in a quite similar manner, except that the lower part is not so long and has only one crosscut, which connects with two places located up the pitch, the total vertical height being around thirty-six feet, the top place acting as the catch basin. Concrete dams were then placed at the necks of each place, making a sump with a capacity of two hundred thousand gallons, or three days water with no pumping. The pump room is located a few feet below the lower dam and between the manway and air course, with steel doors set in concrete stoppings at both ends. This location gives its pump a static head of 205 pounds while the dynamic is 315. Both pumps are set somewhat below the lowest water level in the sumps so the water runs by gravity through their six-inch suctions to the pumps, which makes it almost impossible for the pumps to gather any air whether idle or in operation. The pumps are driven by 200 H. P., 2200-volt, 1725 R. P. M. induction motors through flexible couplings, the pumps and motors being mounted on a common base. The power is brought into the pump rooms through a two-inch conduit which first enters a fuse cut out consisting of three 7500-volt 75 ampere repulsion fuses mounted in a steel box provided with transit board arc chutes. These fuses also serve as disconnecting switches while working on any of the apparatus. Leaving the fuses, it passes in turn through an oil switch, current transformers, starting compensator, and to the motor. Overload protection is provided by 2200-volt trip coils in the compensator, low voltage current coils connected in the secondary of the current transformers and a temperature overload relay connected in the same circuit which also gives protection against open phase. The temperature relay and the 2200-volt trip coils both act to open the release coils in the compensator and the oil switch.
In order that the pumps might run without any attendant other than someone to start them they are each provided with two automatic stopping devices which open the oil switch and the compensator when the water in the sump reaches a predetermined level. One of these devices is a Cutler Hammer pressure regulator which is connected to the sump by a 3/4” pipe. As such a device is subject to failure now and then, and our margin of water over the suction is small, it was decided that there should be another trip of some sort to act in emergency, in case the above failed. This was effected by making a U tube of 1/2” iron pipe with an insulated contact placed in a pipe tee in one leg, at the predetermined water level. The U tube was then filled with mercury and pressure turned in equal to the above level of water. Enough mercury was then added to just make contact. As the sump fills, the mercury is forced up into the open leg of the U tube, 0.438” for each foot of water, and on receding the mercury passing below the contact opens the release coil circuits. As the pressure regulator closes automatically it was necessary to provide some means of checking which trip had functioned the day before, so a counter was fastened to the mechanism which records the number of times it has opened. Then by noting the number up when the pumps are started each day, it can be determined whether the mercury column or the pressure regulator has shut the pump down the last time, the pressure regulator being adjusted to operate a little in advance of the mercury column. In order to smooth the peaks on the station these pumps are operated on night shift, a man being detailed to start them just in time to leave the mine on the man trip, who also checks them over and oils them. When operating each day these pumps run about four and one-half hours, which means 161,500 gallons or 675 tons of water are pumped, which is a little more than one ton of water for each three tons of coal hoisted. These pumps replaced three vertical triplex pumps, two of which ran nearly twenty-four hours a day. The entire installation is in accordance with the Union Pacific Coal Company Code of Standards. (E.R. Henningsen, Chief Electrician, Hanna, Wyo.UPCCEM, 1928)
Union Pacific Coal Company's No. 4 Mine Maps
2018: Union Pacific Coal Company's No. 4 Mine Today
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