Spinning drive mishap

[snopes]

Comment: Folks,
Several years ago, I remember reading a supposedly true story about the
first days of hard drives - large platter. Seems that the folks in the
lab could not get the prototype drive up to speed. As the story goes, the
drive was not completely enclosed and one of the guys came up with the
idea of using a child's toy wheel attached to an electric drill to spin
the drive faster. As the drill and drive came up to speed, the tire
expanded off the wheel. Startled at seeing daylight between the wheel and
hub, the tech jerked the drill away, thus freeing the wheel completely.
The wheel then careened around the lab wreaking havoc and sending the
techs diving for cover.

End of experiment. Surely early computer joke-lore. Sadly, I cannot find
my copy of the story. Any assistance?

[Psihala]

I rather doubt it would have happened as described. By "large platter", I assume the writer is referring to hard-drives intended for use on mainframes. I don't think it likely anyone could have held a drill with a wheel attached to it against the surface of the platter tightly enough to get the platter up to speed and yet steady enough not to get it wobbling. And any wobble at the kind of speeds these things spun at would not have been a good thing.

By the by, I trained on a IBM S/370 system in high school that had banks of large-platter hard-drive assemblies -- both fixed and removable. I hated the removable variety because the stacks weighed about 80 lbs, and were kept on a shelf until the system called for them.

One bit of hard-drive lore that seemed to crop up in virtually every data center I ever worked in was the story of "the scary spindle failure". Hard-drive stacks were comprised of 6-8 platters mounted on a central shaft, or spindle. The spindle was pretty thick -- about 10" in diameter, as I recall. On fixed-drive units, the spindle was attached to a pulley wheel, and driven by a rubber belt similar to a car's radiator fan belt. On the removable drives, the spindle was set on a mating plate attached directly to the drive motor.

There were two types of removable stacks; enclosed and open. In the enclosed type there was a shutter-like door in the back to help keep out dust, and the whole assembly - heads and all - was mounted in the drive. The open type had a removable plastic cover that for all the world looked like something one might put over a cake, and only the stack itself was mounted in the drive. As the story goes, one night there was a spindle failure on one of the stacks after it had been mounted in a drive (I've heard it as involving both types), and the spindle wobbled so badly it started releasing platters(!!!) Almost invariably, one platter would fly out of a drive and lodge itself in an opposite wall.

Nevermind this would have been virtually impossible even if the spindle broke up (which it couldn't). I witnessed my share of catastrophic HD failures over the years - I've long had an example of a head-crash hanging on my wall --but, thankfully, the carnage was limited to read/write heads shaved into teeny-tiny pieces, and the only spindle failures we had were not much more than the belt breaking or the motor bearings seizing up.

~Psihala

[FullMetal]

I worked at a call center with a catastrophic hard drive failure. I was sitting beside (back to back) with a guy who was helping a guy with some weird hard drive problems, and was going through the basics to make sure it really needed replacement. when I hear what sounds like a tray of silverware being dumped into a sink. (I wasn't on the call, this is what I heard through the other guys headset...) he then asks if the caller dropped silverware into a sink, and oh. and the computer bluescreened... ok, we're going to set up a service now. and yes one of the platters in the hard drive had a crack and it splintered which is what caused that noise running at 7200 RPM.

[overyonder]

Actually, over-spinning most kind of platters can lead to some pretty catastrophic failure of the media itself, regardless of the spindles integrity.

As an example, here's a CD-ROM that overspins: https://www.youtube.com/watch?v=FmRV8wNJdKY

OY

[Psihala]

A couple of things:

--25,000 RPM is about twice the speed a CD-ROM drive spins at. The slow-mo guys attached a disk to a Dyson vacuum cleaner motor and spun a couple of discs to failure a few months ago, but these speeds aren't typical in a drive. Anything even a little above the norm speed of 10,000 RPM will shatter a disc with a defect in it.

-- The drives I mentioned in my post were big machines... some were about the size of a mini-refrigerator, the largest about the size of a walk-in closet. They spun somewhere between 10,000-15,000 RPM and the metal platters were made of oxide-coated aluminum alloy (I think - I'm going by memory.)

Today's storage systems use banks of much smaller high-capacity drive assemblies that are more like the drives found in modern PC's.

The point is, even when the bearings at the spindle failed catastrophically on the earliest hard drives, the chances of breaking a relatively thick metal disk disk weren't at all likely. They could do a great deal of damage inside the drive --- especially to the soft-metal head assemblies, but other than the "flying disc" story I relayed in my original post, which I heard everywhere I went in my career, I don't know of any actual example of a disc ever leaving the drive, and certainly not of them shattering.

~Psihala

[Nick Theodorakis]

Pfffft. You ain't seen nothing compared to an ultracentrifuge drive failure.

http://www.ehrs.upenn.edu/programs/l...explosion.html

Nick

[blinkingblythe]

I remember a story about how the magnetic drum broke loose from a
very early (monster sized 1950s era) mainframe hard drive, and the
drum crashed through a door and into a stairwell punching holes in the walls and causing other damage as it careened and bounced down the steps. Don't know how true it is, but early mainframe "hard drives" were huge, heavy beasts
often using multiple heads to read from a heavy magnetic coated metal drum, and the units weighed about the same as a small pickup truck. I think the first ones even used vacuum tubes for their control and logic circuits, and they probaly had to assemble the units on site with ordinary tools, so yeah, I can sort of see how this could happen.

IIRC some of these drives could hold a whopping 100 megabytes of data, which would have been an unfathomable amount
of storage in their time.