Houses weight can vary, a stone or brick house can easily go over 100 tons (2000 lbs/ton). Much more massive structures are moved regularly, including 100 year old 100' high brick light houses (Google Cape Hatteras) All bridges have a design allowable load, and then that is reduced with time, based on inspection. I have done bridge inspections on old railroad bridges. The process is to check for loose rivets and bolts, bent members, and measure thicknesses (whats not rust). This info is taken back to the office, and using the info to calculate new allowable loads. After the Silver Bridge Collapse across the Ohio River, the Federal government (USA) mandated regular bridge inspections. Then the bridges rated and should be posted loads are determined. If the bridge load is not posted, generally it is assumed any load legal on highways is allowed. Any load greater (including oversize) than legal loads requires a permit. As part of the permit process, all bridges to be crossed, dimension restrictions are checked, and the permit defines the route allowed and sometimes the time of the day to be traveled. Within the last week, our County Engineer closed a bridge near us. It is a privately owned bridge on a public road (strange deal). The owner doesn't want to fix it, and the county doesn't want a collapse. The bridge has been posted with reduced loads for some time. But, things happen, design errors, cheating on materials during construction, not identifying a defect during inspection, etc. And then there is the driver bootlegging (cheating) on the legal loads. The Ohio state trooper stopped a truck that was severely overloaded with a large stamping press in Central Ohio. The press started in Central Indiana, and headed to central Pennsylvania. The load was so heavy, that it was not permitted to travel the highways any further. Fortunately there was a railroad track, near, and the load traveled by rail the rest of the way. Many times these bootleg loads travel the back roads, where the likelihood of overloading a bridge is more. Most of the time, structural failures are details like connections or minor members, and almost rarely its a main member (beam or column) that fails. The I-35 bridge last year, Minneapolis, failure was due to some under sized connection plates, corrosion, a contractor overloading with repair construction materials, and finally rush hour traffic loads brought it down. Not unusual, a series of events, probably any one or 2, and no problem. To answer #2, a single car, or even pedestrian traffic may be the limit, or could be in the 100's of tons range. The full range. I drove a Ford Bronco SUV with the family, weight right a 3 tons across the Royal Gorge Bridge (highest suspension bridge in the USA - google for it),with a 3 ton limit. There was considerable pedestrian traffic. As we approached, the foot traffic scattered quickly. We were really rocking the bridge!! :) Rolf wrote: > AGSCalabrese wrote: > >> 3 Questions for an Engineer >> >> Question # 1: >> How much does a house weigh? >> >> Question # 2: >> How much weight can a rural two-lane bridge Hold? >> >> >> >> See >> http://oh-god.com:5080/dir/3Q/ >> >> >> >> Question # 3 >> >> IS THIS BE COVERED BY >> HOUSE INSURANCE, >> CAR INSURANCE, >> OR, >> DOES IT COME UNDER ROADSIDE ASSISTANCE ? >> >> >> > > > http://www.snopes.com/photos/accident/housebridge.asp > > OK. > > Rolf > -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist