Forensic engineering has been defined as "the investigation of failures—ranging from serviceability to catastrophic—which may lead to legal activity, including both civil and criminal". It includes the investigation of materials, products, structures or components that fail or do not operate or function as intended, causing personal injury, damage to property or economic loss. The consequences of failure may give rise to action under either criminal or civil law including but not limited to health and safety legislation, the laws of contract and/or product liability and the laws of tort. The field also deals with retracing processes and procedures leading to accidents in operation of vehicles or machinery. Generally, the purpose of a forensic engineering investigation is to locate cause or causes of failure with a view to improve performance or life of a component, or to assist a court in determining the facts of an accident. It can also involve investigation of intellectual property claims, especially patents. In the US, forensic engineers require a professional engineering license from each state.
Cast iron is a class of iron–carbon alloys with a carbon content more than 2%. Its usefulness derives from its relatively low melting temperature. The alloy constituents affect its color when fractured; white cast iron has carbide impurities which allow cracks to pass straight through, grey cast iron has graphite flakes which deflect a passing crack and initiate countless new cracks as the material breaks, and ductile cast iron has spherical graphite "nodules" which stop the crack from further progressing.
Sir Thomas Bouch was a British railway engineer. He was born in Thursby, near Carlisle, Cumberland, and lived in Edinburgh. As manager of the Edinburgh and Northern Railway he introduced the first roll-on/roll-off train ferry service in the world. Subsequently as a consulting engineer, he helped develop the caisson and popularised the use of lattice girders in railway bridges. He was knighted after the successful completion of the first Tay Railway Bridge, but his reputation was destroyed by the subsequent Tay Bridge disaster, in which 75 people are believed to have died as a result of defects in design, construction and maintenance, for all of which Bouch was held responsible. He died within 18 months of being knighted.
The Tay Bridge carries the railway across the Firth of Tay in Scotland between Dundee and the suburb of Wormit in Fife. Its span is 2.75 miles. It is the second bridge to occupy the site.
Sir William Fairbairn, 1st Baronet of Ardwick was a Scottish civil engineer, structural engineer and shipbuilder. In 1854 he succeeded George Stephenson and Robert Stephenson to become the third president of the Institution of Mechanical Engineers.
Britannia Bridge is a bridge in Wales that crosses the Menai Strait between the Isle of Anglesey and city of Bangor. It was originally designed and built by the noted railway engineer Robert Stephenson as a tubular bridge of wrought iron rectangular box-section spans for carrying rail traffic. Its importance was to form a critical link of the Chester and Holyhead Railway's route, enabling trains to directly travel between London and the port of Holyhead, thus facilitating a sea link to Dublin, Ireland.
The Conwy Railway Bridge carries the North Wales coast railway line across the River Conwy between Llandudno Junction and the town of Conwy. The wrought iron tubular bridge, which is now Grade I listed, was built in the 19th century. It is the last surviving example of this type of design by Stephenson after the original Britannia Bridge across the Menai Strait was partially destroyed in a fire in 1970 and rebuilt as a two-tier truss arch bridge design.
A tubular bridge is a bridge built as a rigid box girder section within which the traffic is carried. Famous examples include the original Britannia Bridge over the Menai Strait, the Conwy railway bridge over the River Conwy, designed and tested by William Fairbairn and built by Robert Stephenson between 1846 and 1850, and the original Victoria Bridge in Montreal.
The Norwood Junction railway crash occurred on 1 May 1891, when a cast-iron underbridge over Portland Road, 60 yards (55 m) north-east of Norwood Junction railway station, fractured under the weight of an express train from Brighton to London Bridge.
The Tay Bridge disaster occurred during a violent storm on Sunday 28 December 1879, when the first Tay Rail Bridge collapsed as a North British Railway (NBR) passenger train on the Edinburgh to Aberdeen Line from Burntisland bound for its final destination of Dundee passed over it, killing all aboard. The bridge—designed by Sir Thomas Bouch—used lattice girders supported by iron piers, with cast iron columns and wrought iron cross-bracing. The piers were narrower and their cross-bracing was less extensive and robust than on previous similar designs by Bouch.
A box girder or tubular girder is a girder that forms an enclosed tube with multiple walls, as opposed to an I- or H-beam. Originally constructed of wrought iron joined by riveting, they are now made of rolled or welded steel, aluminium extrusions or prestressed concrete.
The Inverythan rail accident occurred when a faulty girder collapsed on a 39 by 15 ft single-track railway underbridge between Auchterless and Fyvie. The engine of the freight/passenger train crossed safely, but most of the train fell into the gap onto a road below.
The Bull Bridge accident was a failure of a cast-iron bridge at Bullbridge, near Ambergate in Derbyshire on 26 September 1860. As a goods train was passing over the bridge at Bullbridge, the structure failed suddenly, causing the derailment of the majority of the wagons. There were no serious casualties, but it was a warning of the fundamental weakness of many such bridges on the British rail network.
Structural integrity and failure is an aspect of engineering that deals with the ability of a structure to support a designed structural load without breaking and includes the study of past structural failures in order to prevent failures in future designs.
Gaunless Bridge was a railway bridge on the Stockton and Darlington Railway. It was completed in 1823 and is one of the first railway bridges to be constructed of iron and the first to use an iron truss. It is also of an unusual lenticular truss design.
A balloon flange girder or (colloquially) balloon topper is a form of vertical I-beam wrought iron plate girder, where the top flange, instead of being a simple flat plate, is extended into a hollow tube. When a girder is subjected to a positive bending moment the top flange acts in compression making a flat plate flange more susceptible to local buckling than the balloon flange is.
The Surtees Rail Bridge is a rail bridge on the Tees Valley Line over the River Tees in the Borough of Stockton-on-Tees. The bridge is south of Stockton-on-Tees town centre and just north of the adjacent Surtees Bridge which carries the A66 road. The bridge is built on the site of a series of Tees Bridges alternating between two adjacent crossing sites.
