Safe Times in Confined Spaces

There are plenty of industrial operations out there that take a nave approach to working in confined spaces, or don’t even think in terms of them; the record of industrial accidents in Canada proves that there is also no shortage of poor decisions that have lead to unnecessary deaths.

Maintenance crews at the RH Saunders hydroelectric generating station in Cornwall, Ont., however, take extreme care when working in the station’s 116-plus confined spaces, from the squeezed, doughnut-shaped crawl spaces around the generating units’ shafts, to the roomy but pitch-black scroll cases 42.5 ft below the surface of the St. Lawrence River.

Only those crews trained for specific confined spaces may enter them. There are no exceptions. No-one ever just nips in and out of a confined space to, say, grab a forgotten wrench.

Before anyone enters a confined space, the crew rolls in one of the station’s three crash carts that are stocked with first aid and rescue gear; sets up a fall arrest cable and rescue winch over the entry point; samples the air’s oxygen (O2), lower explosive limit (LEL) and carbon monoxide (CO) levels; and sets up an alarm and communication system. It also prepares a legal document on which a designated attendant writes down who is qualified to enter, details on the air quality, and notes on every time someone enters and leaves.

No wonder the station has gone over eight years without a lost-time accident.

A little incident three years ago demonstrates the merits of the extensive preparations, and drives home the meaning of the old saying, “You can make something fool proof, but you can’t make it damn fool proof.” A crew had set up its welding equipment in a scroll case to begin cavitation repairs on some turbine runner blades. One air tester was monitoring ambient O2, LEL and CO levels and another air tester in the compressed air system’s air purifier was monitoring the air feed to the welders’ helmets.

Coming back from a coffee break, the welders noted that the readings for the ambient air tester were normal, but when they descended into the scroll case they heard the hoot of the alarm for the air tester in the air purifier. It showed CO levels of three parts per million.

This is what the welders discovered: Four levels and nearly 200 ft above them, a man lift in the erection bay had run out of propane. The operator switched to a gasoline-powered man lift, but forgot to open the main doors to ventilate the air. Heavier-than-air CO from the engine’s unburned gas found its way into the compressor room one floor below and was sucked into the welders’ air feed and straight to the very bottom of the station. Said trades management supervisor for mechanical production, Dave Tate, “Everything worked as it was supposed to.”

The Saunders station workers work within the Occupational Health and Safety Act (OHSA), follow corporate safety rules and guidlines in any local documentation, and adhere to the most stringent rules.

In the station, there is a rescue plan document for each different confined space. Each contains information such as work activity pre-conditions, rescue personnel and equipment needs, hazards, rescue procedures, relevant training and a series of pictures showing various steps in the rescue operations.

Maintenance crew familiar with the spaces help develop the documents and, as was done this April during the refinement of the rescue plan for the horizontal lifeline system roughly 45 ft above the erection bay floor, they freely make suggestions that contribute to its final content.

Tate says digital cameras have made a significant difference in the quality of the rescue plans. Before digital, photographs were photocopied and were of poor quality in the documents. But with digital cameras and computers, he says, “The author has total control of the documents: computer at his desk, digital photos … the person who does the work also produces the document. There are no misinterpretations by other persons who prepare the documents but who are not familiar with the content.”

Each crew practices at least one rescue plan a year and everyone receives training on how the rescue equipment works, and its effect on the body. They use a 200-lb mannequin to learn what it is like to manhandle an unconscious co-worker, and work out any bugs in what in some spaces would be fairly complex and arduous rescues; e.g., lolling heads catching on hatch openings (the solution: tape the victim’s head to his arms).

In fact, the confined spaces, which also include elevated spaces such as the Genie boom and powerhouse crane, are varied and challenging enough that the Cornwall City Fire Department regularly sends a detachment to the station to complete their own fireman training.

Maintenance also trains in the “don’ts” of rescues, explains Dale Adams, a first-line manager who looks after civil and mechanical maintenance. “If someone collapses, you have to test the air before sending someone down [to them]. Our training stresses that our observer initiates the rescue, never entering the confined space under any circumstances.

“The observer calls the emergency phone number in the control room and tells the operator what the emergency is. The protocol is to call 911, bring in fire rescue and an ambulance, and page the plant that help is required in such and such an area.”

Before entering a confined space the crew reviews its rescue plan. They will have asked other crews what tasks they are performing, in case they are doing something seemingly simple like painting that could affect their air. If the crew intends to do something that will change the atmosphere, like welding, it will make preparations to ventilate the air and do continuous air monitoring. There is always an observer hovering near the entrance to the confined space.

Good rescue plans, training and execution of procedures are important, but so is the quality of the equipment, says Tate. “Research your equipment. There are companies out there with good equipment and companies out there with poor equipment. This applies not only to rescue equipment but to air testing equipment and what sort of service you will get with the gear you are buying. For example, will sales people come out and support your product?”

The maintenance personnel at Saunders log thousands of hours a year in confined spaces. “My group probably spends the first six months of the year in confined spaces. During rehabs we are in confined spaces all the time,” Tate says.

Staying safe in confined spaces takes effort, but in a line, advises Tate, “Before you enter a confined space, think, think, think. Make sure everybody is well-trained and knows their responsibilities.”

Carroll McCormick is the senior contributing editor for Machinery & Equipment MRO. He is based in Montreal.