Two years later

September 21, 2014, marked two years of recovery from my accident. Looking back at my last major update, about a year ago, I see that, although the healing process continues, not a lot is changing on the surface. My appearance has improved a little more since my February surgery. The left eye now looks normal enough for people to feel comfortable asking why it’s so red—which the rim of the lower lid always is, to varying degrees. I don’t know if that will ever quite go away. My eye is still easily irritated, which can increase the redness. And it still waters a lot, as the cornea continues to dry out and overproduce tears. The eye still hurts at random moments, especially later in the day, sometimes sharply, sometimes deeply. The nerves in my cheek have almost fully regenerated. My eye crinkles almost normally when I smile.

The central vision in my left eye is still gone, though I hold out hope for future medical developments that may reverse the damage (come on, stem cells!). In the meantime, I use my peripheral vision as much as I can to keep my optic nerve active: I sometimes walk around with my right eye shut just for the practice. I still forget sometimes why I can’t see clearly, especially when I first wake up. I have recently been experiencing a fresh bout of grief about the impairment of my sight. I still often bump into things on my left and lose my balance easily. I continue to have trouble concentrating and thinking clearly. I am still trying to figure out how to see as well as I can while I work; my vision varies a lot, and magnifiers and lights only help so far.

I have not entirely recovered my turning skills. I got tendonitis in my right elbow (my dominant arm) in the spring and wasn’t able to work for several months. Add this to the many gaps in work caused by my surgeries and I guess my rustiness is understandable, if frustrating. It has been hard this time to get back into a creative flow, but I am working to hold a steady course through the latest challenges by remembering every day what I haven’t lost (family and friends, my sense of humor, my curiosity, a damn good life) and what I’ve gained (more love, gratitude, a greater sense of connectedness to everything).

My tale of survival

AW29-3-27

The June issue of American Woodturner featured “Safety Matters: From the Eye of a Survivor,” an article I wrote describing my accident and discussing some of what I learned afterward about protecting myself. Please feel free to share it with any woodturners you know; I am hoping that it will save others from injury. It was accompanied by this exercise for determining your own risk at the lathe, along with a table comparing risk values.

New milestones

I have some new recent milestones to note.

First, last Monday, I drove solo for the first time since my accident. The weekend before, I practiced driving in a big empty parking lot and on the empty streets of an industrial park. I managed to park and corner and not run Karen over, so she granted me permission to drive myself to the dentist. I am using extra caution—my left-side blind spot really is a blind spot at the moment—but feel pretty good about being back on the road. I won’t be driving a lot or at night anytime soon, because I am not seeing well in low light and am not adjusting quickly to changes in light, as with oncoming and passing headlights, but it is good to know that I am not entirely dependent on others to get around.

Thursday, I finally finished the vessel I was working on when I had my accident. I epoxied it back together and filled the exterior cracks with turquoise inlay. It is now lucky number 13 in the commissioned series.

The vessel that broke and hit me, now repaired and finished.

The vessel that broke and hit me, now repaired and finished.

Another view of the vessel. I like that these sapwood patches look like eyes--and the left one (on the right in the photo) matches mine at the moment!

Another view of the vessel. I like that these sapwood patches look like eyes–and the left one (on the right in the photo) matches mine at the moment!

 

And on Monday, I started the first of the last four vessels in the series—from another highly cracked log. I used the wire guard on my lathe and wore my riot helmet for protection. The wire guard does interfere with seeing the curve I am cutting, so I probably will not use it for the final external shaping, but I will continue to use it for the rough turning of these vessels and while I hollow the interiors. I am pleased with the riot helmet. It is not too heavy. My head got a little sweaty, but that’s not a big deal for me.

Oh, and today, I used my chainsaw.

Finally, it appears that I will pass a major milestone at the end of February: Dr. Harris says the silicone oil in my eye can come out. She will perform another laser procedure next Tuesday just to make sure my retina is securely tacked down, and three weeks after that, she says, I can have the surgery. I was expecting to have to wait six months from the October surgery, but she says I am ready, or will be (it will be four and a half months by the time the surgery happens). My understanding is that she will replace the silicone oil with saline. I am hoping that this will improve my vision. When you compare photos of the retina in each of my eyes, the right is sharp and the left is dim and blurry, because of the oil. I still won’t have a lens, but I hope that what I can see will be a little clearer and brighter without the oil. And after I heal from that surgery, I can be measured accurately for a new lens, so maybe that will happen sooner than expected too. I don’t want to rush—I want to give my eye all the time it needs to heal as much as it can—but I am anxious to see better.

Safety gear

For safety, I use the Uvex Bionic face shield, which I bought from the Sanding Glove, and a small 3M 7500-series half-mask respirator with P100 filters (other half-mask respirators did not come small enough to fit my face properly—true for most women, I think). Even though I wasn’t wearing my face shield at the time, since my accident, I have looked into whether I could improve that protection. (I also wanted to find out how much protection my face shield would have provided.)

One of the possibilities I considered was the Trend Airshield Pro, which is very popular among woodturners. I discovered, however, that it claims to meet only the “low energy impact” standard for eye protection (http://www.trendairshield.com/specifications.html) and its stated respiratory protection is also lower than what I already have (and it is not NIOSH approved).

The safety standard for eyeglasses and face shields is specified in ANSI Z87.1-2010, which includes general specifications and impact specifications. It is the general specifications that the Trend Airshield Pro meets. My Bionic face shield is rated for the high-impact Z87.1 specifications.

I did the math (see below) and realized that, measured in kinetic energy, the mesquite missile that hit me delivered about 30 times the amount derived from the high-impact Z87.1 specs. Surely, my face shield would have absorbed some of that energy, but I almost certainly would have been injured anyway. Polycarbonate isn’t supposed to break or shatter, but all that energy would have had to go somewhere. Could I have escaped with bruising and a concussion? Would my face bones still have broken? Would the impact have contacted my eye? Does anyone have any experience they can share?

Anyway, I went further with my research and looked into ballistic face shields. These are expensive and heavy and seem to me like overkill (they are also not readily available to civilians). But they did lead me to riot helmets and face shields, regulated under the NIJ 0104.02 standard, with about 15 to 27 times the impact resistance specified under ANSI Z87.1. I ended up buying the lightest one I could find, the Max Pro RD1002X; it weighs 2 lb 3 oz, just a little more than the Trend Airshield Pro. Others weigh 3 lb or more, which I thought might be a bit heavy for prolonged wearing. I should receive it in a week and will report on how it feels.

Max Pro RD1002X anti-riot helmet

Max Pro RD1002X anti-riot helmet

You may notice that the impact resistance of the riot helmet is still not equal to the impact I sustained in my accident; at best, it is 15% too low. I balanced the impact resistance against potential comfort (weight) and cost and also reasoned that damage to this helmet would still mean considerably reduced damage to me.

My intention is to wear my Bionic face shield with my respirator when turning most things (most of what I turn is small and light), but to wear the Max Pro with my respirator when turning heavier pieces, especially when working with cracked wood. I also installed the wire guard that came with my Jet 1642 lathe and will see how that feels. I have read that others don’t like using it, but I’ll try it to see if it interferes with visibility or tool use.

The wire guard on the Jet 1642 lathe.

The wire guard on the Jet 1642 lathe.

For the technically minded among you, below is a summary of the kinetic energy figures derived from the specifications and my calculations. I give the foot-pound equivalents for kinetic energy for those more familiar with the units used in ballistic specs.

KE Unit Accident Z87.1 High Velocity Z87.1 Penetration 0104.02 Impact 0104.02 Penetration
Joules 127 4 6 111 88
Ft-lb 94 3 5 82 65

Formulas:

  • velocity of falling object = √(2 × height from which dropped × acceleration due to gravity)
  • kinetic energy = .5 × mass × velocity²

My accident:

  • 1-kg piece from a 10″- (.254 m–) diameter vessel turning at 1200 rpm
  • velocity = (.254 × 3.14 (pi) × 1200) / 60 sec = 15.95 m/sec
  • 1 kg traveling @ 15.95 m/sec
  • .5 × 1 × 15.95² = 127.201 joules (93.82 ft-lb)

ANSI Z87.1 tests (Bionic face shield):

    High velocity:

  • ¼-inch steel ball (.001046 kg) traveling @ 300 ft/sec (91.44 m/sec)
  • .5 × .001046 × 91.44² = 4.373 joules (3.23 ft-lb)
    High mass impact:

  • 500 gm (0.5 kg) pointed projectile dropped from 50 inches (1.27 m)
  • velocity = √(2 × 1.27 × 9.81) = 4.99 m/sec
  • .5 × .5 × 4.99² = 6.225 joules (4.59 ft-lb)

NIJ 0104.02 tests (riot helmet):

    Impact:

  • 5.1 kg traveling @ 6.6 m/sec
  • .5 × 5.1 × 6.6² = 111.078 joules (81.93 ft-lb)
    Penetration (pointed striker):

  • 3 kg dropped from 3.00 m
  • velocity = √(2 × 3 × 9.81) = 7.67 m/sec
  • .5 × 3 × 7.67² = 88.243 joules (65.08 ft-lb)

This is a simplification, of course. The numbers don’t take into account air resistance, drag, pressure, or other factors. They just gives me a means of meaningful comparison.

Addendum

Australia and New Zealand have higher impact standards. (Their medium impact standard is close to the ANSI Z87.1 impact standard—at least for eyeglasses. Cannot find their face shield specs.) Their test for high velocity uses a 6.35-mm (¼-inch) steel ball traveling at 120 m/sec. This yields a kinetic energy figure of about 7.5 joules, compared to 4 joules under Z87.1. The Triton Powered Respirator meets this higher standard, and its shield is indeed thicker than that of the Bionic face shield. I did not check the helmet or respiratory standards for this device.

Oops! The Triton respirator may no longer be available: I can’t find it even on the Triton web site.

What happened

I was turning an end grain hollow vessel from a short segment of a badly cracked mesquite log. The final form at the time of the accident was about 10 inches in diameter at its shoulder and 6 1/2 inches tall.

I knew it was a dangerous piece of wood from the beginning, and I had been treating it as such. The only reason I was turning such a dangerously cracked piece of wood was to fulfill a specific commission that called for a lot of stone inlay.

I had turned down the exterior and shaped it between centers, including cutting a tenon to chuck it for hollowing, at speeds ranging from 150 to 450 rpm. I had wrapped the exterior with duct tape at the shoulder and along the taper before beginning to hollow. (With 20/20 hindsight, I would instead have swaddled the piece in plastic wrap.) I had hollowed the vessel at varying speeds up to 550 rpm. I had deliberately left the walls very thick, an inch and a quarter to more than two inches thick, out of caution because of the cracks. After hollowing about as much as I planned to, I turned up the speed to close to 1200 rpm to make a couple of clean-up passes on the interior. Note that when I was making these interior cuts at the high speed, I was positioned out of the line of fire, should the vessel have broken at that time. Although I normally dial my speed up from and down to zero, in this case, after I found a nice fast speed without vibration that allowed me a clean cut on the interrupted interior surface, I hit the power button to stop, check my cut, and restart for another cut or two. I stopped and restarted in this way once or twice, possibly three times.

Then I stopped to answer a phone call.

Without the interruption, what would likely have happened next, based on previous practice, is this: I would have felt the interior surface, sucked the shavings out, taken a last look, and, deciding to call it quits on the interior, I would have reached over at that point to turn the speed dial back to zero without turning the lathe back on. That would have completed the rhythm of that sequence.

Answering the phone call interrupted that sequence. Further, it changed the protection I was wearing. Up until that point, I had been wearing my half-mask respirator, my glasses, and a full faceshield. I took off my faceshield and dropped my respirator to answer the phone. After hanging up, I pulled the respirator right back up, out of habit. Instead of putting the faceshield back on, however, I used the opportunity to take a careful look at the vessel.

I had cut as much as I dared from the interior. I saw that the exterior curve near the mouth wasn’t quite what I wanted. I repositioned the tool rest from inside the vessel to parallel to the top, and I pulled the power button on. I wanted to look at the vessel spinning so that I could see beyond the duct tape to see if I wanted to make any other cuts before calling it quits for that stage of the turning.

Now, despite what I just implied a couple of paragraphs back, I can’t really blame the interruption for what happened. Interruptions happen, and I knew from previous experiences the danger of turning on the lathe when it is already set at a high speed. I have in fact been trying to train myself to habitually and automatically check the relative position of the speed dial before turning the lathe back on after any interruption. This I plainly failed to do, and I have to take full responsibility for my failure to do so.

When I did turn the lathe on, the high speed didn’t trigger any alarms for me. I often turn at high speed, because I normally turn much smaller, more delicate pieces, often with interrupted surfaces. And I was only looking, after all. I confess I always thought of faceshields as protecting my eyes from flying chips, not as protecting my head and face from random missiles.

The irony is that my next step would have been to turn the lathe off. I have a clear image of the piece as I was last seeing it. I couldn’t have touched up the surface I was dissatisfied with even if I had wanted to: the duct tape was in the way. I would have turned off the lathe and waited till a later stage to touch up that curve. Although I had a tool in my hands, it wouldn’t have been the appropriate tool for such touchup, and I didn’t have it raised for use. If I had, my forearm might have provided some defense. As it was, I was just looking. I may have even been leaning in to look. It was a peaceful, unthreatening, undangerous moment.

Until it wasn’t.