Engineering: May 2009 Archives

Engineering expert Richard Roth testified Thursday in Cape May, NJ, in the vehicular homicide case of New Jersey state trooper Robert Higbee.  Roth said Higbee was driving over 70 mph seconds before he crashed into a minivan in the September 2006 crash that killed teenage sisters Jacqueline and Christina Becker.

The expert testified regarding information from the police car's data recorder. Roth said it showed the trooper drove between 70 and 80 mph before slamming on the brakes just before the crash. The defense lawyer said the trooper ran a stop sign while trying to catch up with a speeder.

Information from Philly.com.

Geology expert Robert Curry testified Monday in a federal court hearing about the stretch of Nevada canal that burst and flooded hundreds of homes in 2008. Federal inspectors had warned a Nevada irrigation district in 2005 that the district's irrigation system about 30 miles east of Reno was at a "high hazard" level.

Homeowners who fear another flood this spring are seeking a court order to slow water flows in the canal that runs through Fernley and delivers water to more than 2,500 ranchers and farmers for their crops and livestock.  The expert testified on behalf of flood victims and said the flood happened because of a flawed, century-old canal design, settling soil, inadequate maintenance and a rapid rise of water after a storm.

Former irrigation district employee Don Watson testified before U.S. District Court Judge Lloyd George that he reported the canal leak about October 2007, some three months before the flood.

Excerpted from MercuryNews.com.

Engineering expert Frank Baumann, PE, is a registered corrosion engineer, certified water treatment operator and certified water quality analyst. Here he writes on the internal corrosion of plumbing.

Some of the initiating factors include manufacturing defects such as internal surface imperfections, poor workmanship in the installation of the pipe (flux runs, excessive heating, stagnation-formed films in copper pipe, overthreading in steel pipe, faulty joints, direct contact of dissimilar metals [galvanic corrosion], etc.) and wrong (too small) pipe sizes, resulting in excess water velocity thus causing erosion corrosion.

So does the water play any role in this? Of course it does. For corrosion to occur, the corrosion curent must flow from the anode to the cathode. This requires a conductive medium – the water. All waters (with the exception of pure distilled water) are capable of carrying the corrosion current. And some waters are indeed more aggressive than others. Frequently, the water is implicated only inasmuch as it sustains the corrosion reaction – but the water is not the primary cause for the corrosion to occur.

The owner of Stockbridge Funeral Home is suing the town of Exeter, NH, over flooding he says was caused by the town culvert. Stockbridge and his engineering expert, William Gallot, testified in court on Thursday. They argued that the development located upland from the funeral home contributed to flooding on the property.

Exeter attorney Catherine Costanzo said it was information presented by Gallot that the town used to establish its points. Costanzo said the town submitted regulations showing the standard of care in 1975 — when the culvert was installed — and that it was only meant to withstand a 15-year storm. The storms that caused the flooding were approaching or exceeding 100-year storms, she said.

Excerpted from SeacoastOnline.com.

Engineering expert Frank Baumann, PE, is a registered corrosion engineer, certified water treatment operator and certified water quality analyst. Here he writes on the internal corrosion of plumbing.

Among a homeowner’s more traumatic experiences, especially if the home is fairly new, ranks the telltale wet spot on the living room carpet (if the plumbing is in the slab), or the soggy bits of not-so-dry-wall (if the plumbing runs overhead.) An inspection is likely to reveal more than just a single trouble spot, and the usual verdict is an expensive replumbing job. The homeowner is upset and wants to be made whole, so he sues the most likely culprit – the water company. After all, it was the water that caused the problem. Or was it not?

The corrosion engineer, in trying to determine the most probable cause of a plumbing system failure, must look for, not just one, but two factors: 1) What initiated the problem, and 2) what propagated it.

There are some aggressive (corrosive) waters which will dissolve metals with which they come into contact, just as there are some saturated ones that deposit heavy scale in water heaters and hot water systems. An aggressive water will usually cause general corrosion. That is, it will dissolve metal at a uniform rate throughout the internal pipe surfaces. The loss of metal at any one point is thus very minor, and the system generally attains its design life. If the same loss of metal were to be confined to just a few small points in the system, however, the loss of metal at those ‘pits’ may result in perforation of the pipe and catastrophic failure of the system due to ‘pitting corrosion’. While there are some waters with a greater propensity to cause pitting, the great majority of pitting corrosion is initiated by factors other than the water.