I love the submarine example. A true testament to the strength of lignin…nature’s polymer.
I seem to remember the original post mentioning that they didn’t like steel because of the chance for slippage of the blocks due to hydraulic fluid. My suggestion would be to use steel supports with wooden support surfaces. Then the wood becomes the anti-skid piece; but doesn’t have to hold the entire load. Personally, I trust wooden blocks with my life all of the time when working on cars, farm machinery , etc… However, you do have to understand the nature of wood. There are certain orientations of grain and defects that could be a recipe for disaster. If you are looking for a reference, one that may help is “Understanding Wood” by Hoadley. I have a copy at home. I know that it provides some strength numbers for various species and orientations of wood. Chris Maxwell Design/Compliance Engineer Anritsu _____ From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Price, Ed Sent: Tuesday, March 21, 2006 9:22 AM To: emc-p...@ieee.org Subject: RE: Off Subject - Load Rating of Wood Blocks > -----Original Message----- > From: ejearnst [ mailto:ejear...@accuray.com] > Sent: Monday, March 20, 2006 5:10 PM > To: emc-p...@ieee.org > Subject: RE: Off Subject - Load Rating of Wood Blocks > > Hi, > As an ex-nuclear submariner, one of the neatest things I've > seen is a submarine in a dry dock with only a row of blocks > down the centerline holding it up. The blocks were made of oak... > > http://www.arco.navy.mil/build.htm > Eric Those scenes are also a testament to the accuracy of the hull construction. Designing the hull is one task, but since a vessel usually needs to be hauled during its usable life (hull cleaning, inspection, systems upgrades, battle damage), the designers other big task is to specify the cradle needed for a dry-dock. I find it interesting that the cradle builders are using flexible steel tape rulers to measure the block positions, so perhaps the tolerance of the blocks is +/- 1/8"? Ed Price ed.pr...@cubic.com WB6WSN NARTE Certified EMC Engineer & Technician Electromagnetic Compatibility Lab Cubic Defense Applications San Diego, CA USA 858-505-2780 (Voice) 858-505-1583 (Fax) Military & Avionics EMC Is Our Specialty - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
