Machine & Operator Safety
Ye olde days
By John Martin
By John Martin
Dec. 11, 2015 – Machine safety isn’t what it used to be — thank goodness for that.
I began working as a machinist in 1970. I turned aluminum dials for Hollywood motion picture cameras on Manhattan’s West Side. I machined housings for Digital Equipment Corporation minicomputers in a job shop on Route 128, Boston’s “technology highway.” I refurbished parts for sewing machines in New York City’s garment district, and machined one-offs for faculty experiments in the Chemistry and Physics departments at New York University. I ran machining centres that tore up aluminum to make aerospace parts in Oakland, Calif.
I never saw a machine guard in seven years of work — everything was open to the touch (although to be fair to the OEMs, shop owners often removed guarding for easier access). In a Bronx, N.Y., job shop, on the first day of work, I reported to my lathe, reached in to open the chuck, and yanked my hands out when I realized it was spinning full tilt. Turns out the foreman, an old-school guy from what was then Yugoslavia, started the machines 10 minutes before each shift to mitigate temperature changes that might affect the precision work.
As a tool-and-die apprentice at a manufacturer of electrical products, I had to do some surface grinding, something I hadn’t done before. When I saw something askew with the part held by the magnetic chuck as it fed toward the wheel, I reached in instinctively to make the adjustment and got caught by the abrasive disk. I was let off work for the day with a bandaged finger and a woozy feeling. I still have the scar where I almost lost the tip of my pinky.
Without guarding, we would reach in, insert stock into a lathe chuck, and tighten the chuck manually with a T-shaped key. The most critical part of the operation, besides rotating the part gently as you closed the jaws to ensure concentricity, was to remove the chuck key before starting the machine. One time I forgot, cranked up a lathe, and the metal key ejected like a missile from the whirling chuck, whistling past my head and across the shop.
The absence of machine guarding also intensified our exposure to cutting fluids. At the Oakland aerospace shop, the hot spot where the high-revving end mill met the metal was flooded with coolant. Blue-green liquid would splash all over me and I would inhale the mist. I broke out in a full-body rash; I was tingling, on fire everywhere. I went to the hospital for tests.
Today’s machinery is protected by mechanical guards, enclosures and interruption devices like light curtains and lockouts. Services and software pitch in too, as with all aspects of manufacturing. Various firms offer assessment, training and start-up services around machine safety. As members of the manufacturing industry, we must all play a part in promoting a culture of machine safety in the workplace. This brings to mind Machine Safety Management, a firm that was started by Jack Reiter, who as a kid saw his dad nearly lose his thumb trying to find the Off switch while tussling with a table saw. Reiter and his dad went on to design a hands-free emergency stop control, and his company now offers software to help businesses conduct, store, and manage machine safety audits and risk assessments for their equipment.
I still get a kick out of the scar on my finger — but only in retrospect. I remember the terror at the time — thinking my hand was going to be dragged under the aluminum oxide wheel while I fumbled for the kill switch. I remember sitting in the hospital being tested after the coolant exposure, wondering what was going to happen. My heart leapt into my throat when the chuck key was thrown from the lathe — at the exit velocity of a ball exploding off the bat of Jose Bautista and into the left-field seats at Rogers Centre.
Make sure you’ve got a good machine safety program. Give today’s machinists Tim Cards from Tim Hortons for their compliance, instead of scars.
John Martin is an ex-machinist who writes about manufacturing, software and IT from his base in Ithaca, N.Y.
This column previously appeared in the November/December 2015 issue of Manufacturing AUTOMATION.