Thirty-five years ago this week, at 4:08 p.m. on April 15, 1981, a methane coal dust explosion killed 15 miners at the Dutch Creek No. 1 mine. The blast occurred in the 102 longwall-development section, killing the miners working in the 102 Section, and in the other producing area, the Slope Section of the mine. Six miners who were working in other areas of the mine at the time of the explosion survived the blast. Three of them were injured by the explosion and rescued while three others escaped uninjured and reached the surface of the mine.
The Dutch Creek No. 1 Mine was a coal mine located about 9 miles southwest of Redstone, Colorado (Pitkin County), off state highway 133. Owned by Mid-Continent Resources, Inc., the mine was one of five mines in a complex operated by this company. The mine employed 83 people, with 79 working underground in two coal-producing shifts and one maintenance shift each day.
Dutch Creek No. 1 was known as a “gassy mine” – because of high methane liberation Dutch Creek No. 1 Mine was initially designated for a 5-day spot inspection schedule.
MSHA investigators concluded that an outburst of coal and methane occurred at the face of the No. 1 entry on the 102 Section, releasing large amounts of methane and coal dust, creating an explosive methane/air/coal dust mixture (methane gas comes from coal and is explosive at levels of 5 -15% of the atmosphere).
The outburst, investigators concluded, was caused by extensive stresses exerted on the coalbed and face by the massive overburden (or the soil, stones and plant life above the mine) and other geological conditions in the mine. The explosion occurred when methane had accumulated around the continuous mining machine and migrated into the compartment housing the light switch and the light switch controlling the lighting system on the continuous mining machine was turned off.
The electric components of the switch were housed in an explosion-proof compartment which, while designed to be explosion-proof, had not been maintained in permissible condition. The cover of the compartment had not been properly installed because it had been closed onto an insulated wire inadvertently left in the plane flange joint of the compartment, causing an opening measuring about 0.015 of an inch, about the equivalent of a sewing needle. This opening permitted the potentially explosive methane to migrate into the compartment. The methane was then ignited by an arc caused by operation of the switch.
The escaping flame and burning material ignited the explosive methane-air mixture in the face area of the No. 1 entry. The nine miners working in the 102 Section and the six working in the Slope Section ranged in age from 19 to 43. All perished in the explosion.
Agency investigators pointed to three conditions and practices that led to the cause of the explosion: poor lighting system installation, use of unqualified personnel, and poor testing of conditions. The report stated:
- The lighting system was not installed in accordance with the wiring diagram that was submitted by Mid-Continent with their request to install the lighting system and approved by MSHA. The lighting system on the continuous mining machine was not de-energized when the methane monitor activated as the methane content exceeded 2.0 percent.
- The installation and wiring of the two-pole light system control switch and the installation of the cover of the explosion-proof compartment was not performed by a person who was qualified within the meaning of Section 75.153, 30 CFR or under the direct supervision of a qualified person.
- The flame path under the cover of the explosion-proof compartment was not properly tested to ascertain that the compartment was in permissible condition after the cover was installed.