Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site calmasd.UUCP Path: utzoo!linus!decvax!ittatc!dcdwest!sdcsvax!sdcc3!sdcc6!calmasd!rfc From: rfc@calmasd.UUCP (Robert Clayton) Newsgroups: net.columbia Subject: Re: Columbia's Tiled Damaged by Rain Message-ID: <521@calmasd.UUCP> Date: Mon, 5-Aug-85 16:57:34 EDT Article-I.D.: calmasd.521 Posted: Mon Aug 5 16:57:34 1985 Date-Received: Wed, 7-Aug-85 04:20:47 EDT References: <4010@alice.UUCP> <199@mot.UUCP> Organization: Calma Company, San Diego, CA Lines: 32 > how interesting! Columbia's tiles survive atmosphere re-entry only to get > beat up by a rainstorm (which you'd think would be gentle) coming at it at > a couple hundred mph. > -- > << Generic disclaimer >> > Fred Christiansen ("Canajun, eh?") @ Motorola Microsystems, Tempe, AZ > UUCP: ihnp4!{attunix, btlunix, drivax, sftig, ut-sally!oakhill}!mot!fred > ARPA: oakhill!mot!fred@ut-sally.ARPA AT&T: 602-438-3472 Do not underestimate the power of any massive particles in a high velocity fluid stream. Commercial sand blasters operate at 60 mph and are used to remove heavy corrosion from steel and to erode stone surfaces in buildings. Shotblasters operate at 100 mph and are used for shotpeening metal parts - a work hardening process used to strengthen steel castings and forgings. In the last century, hydraulic mining was used to wash away mountain slopes to expose pay dirt in California's gold country. These hydraulic cannons can be seen today along the roadside set up as historical monuments. They are the size of field artillery pieces. From the look of them, it is unlikely they would have operated above 50 mph. Extensive flumes and aquaducts were built to channel the water to them. Hydraulic mining is used today to mine iron ores. A several hundred mph blast of water is extremely destructive. Fortunately in a storm the water is dispersed, but I suspect it compares to a sand blaster in terms of destructive potential. Today, commercially available cutting tools use high pressure water jets to cut steel plates 6 inches thick. Water is not harmless. Bob Clayton GE Calma, San Diego R&D (619) 458-3400