From Ducts To Dresses

THAT WAS AN EXCELLENT article on the substance that fixes anything and everything, duct tape (“Object Lessons,” by Curt Wohleber, Summer 2003). A student in my heat-transfer class last spring semester made a book bag entirely out of the tape, complete with pockets for a calculator and pencils. I found it a classic example of the innovative spirit. Here is a picture.

Tom Lawrence
LAFAYETTE, IND.

From Ducts To Dresses

OUR DAUGHTER, BARBARA McLachlan, is a high school teacher in Durango, Colorado. She entered a contest in which she had to dress as the goddess of something, and she chose to be a goddess of duct tape. She won first prize.

William O. Hall
LAKEWOOD, COLO.

From Ducts To Dresses

CURT WOHLEBER WROTE ,“It may or may not be reassuring to know that there is … a grade of duct tape made specifically for use in nuclear reactors.” I would like to provide some reassurance about that and explain why there is such a special grade. Unlike the mechanics in the article using duct tape to patch a hole in the window of a passenger jet, no one does anything so bold at a nuclear power plant.

Nuclear power plants are shut down every 12 to 18 months to refuel. During these refueling outages, workers conduct maintenance on plant components. Work areas are roped off, and warning signs are posted to inform workers about various hazards (radiation areas, contaminated areas, overhead hazards, etc.). Attaching ropes and signs to piping with tape is a common practice for quickly erecting these temporary barriers. When the tape is removed, some of the adhesive remains on the piping. The piping systems that contain the reactor coolant are made of stainless steel. Chemical contaminates such as chloride, fluoride, and sulfate can lead to cracks in stainless steel that is kept hot over time.

The nuclear grade of duct tape is tested to meet very low levels of contaminates in the adhesive and the tape itself. When these specifications are met, the time and effort to remove all the tape and adhesive from the piping isn’t required, and radiation exposure for plant workers is reduced because they spend less time in radiation areas. Nuclear duct tape is graded not to provide a super pressure boundary but rather to preserve stainless-steel piping systems.

Masking tape is used in nuclear power plants at times to seal seams in the protective clothing donned to work in radioactively contaminated areas. It is special chloride-free masking tape, so that it can be incinerated at licensed wasteprocessing facilities. The need for that tape has been greatly reduced by the use of Velcro garment seals and neoprene wristbands that cover the sleeve-to-glove interface.

Clint Miller
Principal Radwaste Engineer
Diablo Canyon Power Plant
PISMOBEACH, CALIF.

Here’s To Helmets

I WAS AMUSED TO READ , in “Hardheaded Logic” (by Edward Tenner, Summer 2003), that the M-I helmet’s unofficial uses included “tent-peg pounder.” In my outfit (407th Infantry, 102d Division), using the helmet to pound tent pegs into the Texas hardpan was a threatened, though never exacted, summary courtmartial offense, for the simple reason that you could seriously dent or even rupture its thin metal. As this realization sank in, via many an illegal experiment, we fervently expressed the hope that our tent pegs were made of sterner stuff than were the enemy’s bullets.

That hope was exploded for me on the Siegfried Line, along with the presumption that, in Tenner’s words, “the smooth, round shape maximized the chance that a bullet would bounce off.” After one attack a platoon buddy proudly showed me his M-I helmet and the hot-metal burn on his temple. The helmet had an elongated entry hole forward of the temple and two exit holes in its back, signifying that the first bullet had rotated the helmet approximately 15 degrees in the time between the respective exits of the two bullets. I myself was fortunate in needing my M-I to shelter my head only from raining clods of sugar beets and dirt while I was pinned down in a many-hours-long barrage from a German 8 8-mm gun.

Although I was in the 9th Army, not the 3d, I’ve always had mixed feelings about Gen. George Patton, so I was pleased to see him credited with supporting the “webbed footballhelmet suspension,” which was a godsend for keeping our K-ration issues of olive-drab toilet paper dry under its webbing, even under unlikely circumstances. When our assault boat was hung up on an uprooted driftwood tree toward the farther bank of the Roer River, we had to bail out into chest-deep water. Holding my M-I Garand rifle above me while wading ashore, I stepped into a depression that was well over my head. Bringing down my hands as I stumbled caused the rifle to hit the forward lip of the helmet and flip it off. After dropping to my hands and knees to crawl up and out of the hole and then stand up under the brilliant light of multiple flares, I looked wildly about for my helmet. There it was, floating rapidly downstream in the floodwater current. “My toilet paper!” I mentally yelled. I plunged after it. The paper remained dry throughout.

A. James Crawford
FAIRFIELD, CONN.

Here’s To Helmets

THE ARTICLE ON HELMETS was especially timely for us in Chicago, or at least for those of us who followthe Chicago Cubs and in particular Sammy Sosa. In an April 20 game against Pittsburgh this year, a pitched ball shattered Sosa’s helmet. He later said of his headgear, “That’s the helmet that saved my life, so I’m going to put it out as a trophy.” And then he added, “Seriously, I’m going to carry that one around with me like my baby.”

Roch Shipley
NAPERVILLE, ILL.

Here’s To Helmets

I WAS QUITE SURPRISED TO read that cyclists’ head injuries have increased along with helmet use, so I went to the U.S. Consumer Product Safety Commission’s Web site (www.cpsc.gov) to view the statistics, and every report I read states quite clearly the opposite. Are you sure that while ridership declined in the decade after 1991, head injuries increased by 51 percent per bicyclist?

From Ducts To Dresses

Edward Tenner replies: CPSC statistics show that bicyclists suffered 66,820 head injuries in 1991 and 73,750 in 2000, and other statistics show a considerable decline in ridership. The numbers are confusing and sometimes conflicting though. Helmets undeniably save lives and prevent disabling head injuries, and if I were a cyclist I would wear head protection. However, techniques of safe motoring and cycling may be even more important for public health than the technology of the helmet.

Greg Landon
KENT, WASH.

Cernan Lives

IN YOUR SUMMER 2003 issue you refer to “the late astronaut Eugene Cernan” (“Notes From the Field: Spoons From Outer Space,” by Frederic D. Schwarz). Cernan is very much alive and well.

Paul losée
HOWELL, N.J.