A manual metal lathe located in the Bray Laboratory Building machine shop is similar to the machine that killed Yale senior Michele Dufault on April 12.
The ONLY conceivable safety device that may have prevented this death is not on these lathes....a foot brake. I don't believe Michele, once she was caught in the spindle, could possibly have had the presence of mind to blindly hit the E-stop or reach the on/off lever and shut it off. A foot brake, however, extends the length of the bed of the lathe and not only turns off the spindle, but stops it almost instantly.
That being said, there is nothing that can make a manual lathe any less dangerous outside of good safety training, and an operator who strictly follows those safety rules. One of the most basic safety rules concerning the operation of ANY rotating equipment is to not work around it with anything attached to you...clothing, jewelry, HAIR....that can be caught and pull you in. In the Navy we were constantly reminded that most safety rules were written in blood. Something tells me Yale was deficient in getting that point across.
Yep, that’s what I was thinking too - a foot brake on a gearhead machine might have done something. The e-stop... even on the carriage... I dunno..
Small bit of reference: The lathes pictured have foot brakes (the red treadle in the bottom center of the machine).
According to Yale and the OSHA report, the lathe in question was a 1962 Clausing. The OSHA report references a “Harrison-Claussing” but that’s nonsense. Clausing was making lathes in 1962 under either the name Clausing or Atlas. Harrison is simply the English outfit that bought up the remains of Atlas/Clausing later in the 70’s. I’m going to go out on a limb and say that the lathe was likely a Clausing, and OSHA is simply pointing at the company that carries parts under the name ‘Clausing’ today, which is Harrison-Clausing, part of the “600 Group” out of the UK that puts UK/US names on Chinese pig iron and calls it a “precision machine.” But don’t get me started on crap machinery that comes out of China or we’ll be here all week.
1962 Clausings, to my knowledge (and I’ve only looked at a few early vintage Clausings - 6300, 5300, 5400 and 4900 series machines) weren’t equipped with either an e-stop or a spindle brake. They were old-fashioned belt-drive machines, like the older South Bend or Sheldon machines.
The OSHA report said that her hair became wrapped around the lead screw, not the workpiece. For people who are not familiar with lathes, on rottndog’s picture here, look at the front of the lathe: You will see a red knob about the middle of the machine, just to the right of the carriage. Look above that, the dark shaft that runs horizontally the length of the bed. That’s the leadscrew on a lathe, it drives the carriage automatically when feeding or threading on a lathe. The leadscrew rarely turns all that fast, and doesn’t have but a fraction of the horsepower available to the workpiece, but it is still enough to pull someone in.
Now, for the people here who haven’t operated lathes: The lathes that rottndog just pictured there are actually fairly small machines, but are probably not that much different in size than anything you’d see in a school lab environment. Those look like 13x40 machines, ie, an ability to turn a 13” diameter workpiece up to 40” long. That’s not a very large lathe at all. As rottndog says, nothing can take the place of training and awareness by the operator. No amount of safety guards can make rotating machinery safe.