Kirkaldy Testing Museum
Encyclopedia
The Kirkaldy Testing Museum is a museum in Southwark
Southwark
Southwark is a district of south London, England, and the administrative headquarters of the London Borough of Southwark. Situated east of Charing Cross, it forms one of the oldest parts of London and fronts the River Thames to the north...

, south London
London
London is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...

, England
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

, located on the site of David Kirkaldy
David Kirkaldy
David Kirkaldy was a Scottish engineer who pioneered the testing of materials as a service to engineers during the Victorian period. He established a test house in Southwark, London and built a large hydraulic tensile test machine, or tensometer for examining the mechanical properties of...

's testing works. It houses Kirkaldy's huge testing machine
Machine
A machine manages power to accomplish a task, examples include, a mechanical system, a computing system, an electronic system, and a molecular machine. In common usage, the meaning is that of a device having parts that perform or assist in performing any type of work...

, along with many smaller more modern machines. It is open on the first Sunday of each month.

David Kirkaldy

Kirkaldy worked at Napier shipworks, but left in 1861 and over the next two and a half years studied existing mechanical testing methods and designed his own testing machine. William Fairbairn
William Fairbairn
Sir William Fairbairn, 1st Baronet was a Scottish civil engineer, structural engineer and shipbuilder.-Early career:...

 had pioneered tensile strength
Tensile strength
Ultimate tensile strength , often shortened to tensile strength or ultimate strength, is the maximum stress that a material can withstand while being stretched or pulled before necking, which is when the specimen's cross-section starts to significantly contract...

 measurement as well as assessing creep
Creep (deformation)
In materials science, creep is the tendency of a solid material to slowly move or deform permanently under the influence of stresses. It occurs as a result of long term exposure to high levels of stress that are below the yield strength of the material....

 and fatigue
Fatigue (material)
'In materials science, fatigue is the progressive and localized structural damage that occurs when a material is subjected to cyclic loading. The nominal maximum stress values are less than the ultimate tensile stress limit, and may be below the yield stress limit of the material.Fatigue occurs...

 on large structures as well as small. Entirely at his own expense, Kirkaldy commissioned this machine from the Leeds
Leeds
Leeds is a city and metropolitan borough in West Yorkshire, England. In 2001 Leeds' main urban subdivision had a population of 443,247, while the entire city has a population of 798,800 , making it the 30th-most populous city in the European Union.Leeds is the cultural, financial and commercial...

 firm of Greenwood & Batley, closely supervising its production. Aggrieved over the slow rate of manufacture, after fifteen months he had it delivered to London still unfinished, in September 1865. The testing machine is 47 feet 7 inches long, weighs some 116 tons, and was designed to work horizontally, the load applied by a hydraulic cylinder
Hydraulic cylinder
A Hydraulic cylinder is a mechanical actuator that is used to give a unidirectional force through a unidirectional stroke. It has many applications, notably in engineering vehicles.- Operation :...

 and ram. The machine is still held in working order at the Kirkaldy Museum in Southwark, although problems have occurred with the gaskets which seal the cylinders.

He also developed methods for examining the microstructure
Microstructure
Microstructure is defined as the structure of a prepared surface or thin foil of material as revealed by a microscope above 25× magnification...

 of metals using optical microscopy. It involved cutting sections, polishing the sections and then etching to reveal different constituents.

Tay bridge disaster

Kirkaldy famously tested many samples taken from the first Tay railway bridge for the official Inquiry on the Tay Bridge Disaster
Tay Bridge disaster
The Tay Bridge disaster occurred on 28 December 1879, when the first Tay Rail Bridge, which crossed the Firth of Tay between Dundee and Wormit in Scotland, collapsed during a violent storm while a train was passing over it. The bridge was designed by the noted railway engineer Sir Thomas Bouch,...

. He confirmed that the wrought iron
Wrought iron
thumb|The [[Eiffel tower]] is constructed from [[puddle iron]], a form of wrought ironWrought iron is an iron alloy with a very low carbon...

 tie bars failed at their connections to the cast iron
Cast iron
Cast iron is derived from pig iron, and while it usually refers to gray iron, it also identifies a large group of ferrous alloys which solidify with a eutectic. The color of a fractured surface can be used to identify an alloy. White cast iron is named after its white surface when fractured, due...

 columns of the bridge, when he tested intact tie bars with complete lugs still attached. The attachments were cast iron lugs which fractured at the bolt holes, and numerous fractured lugs were found after the disaster lying on the piers. The critical strengthening elements were much weaker than had been supposed by Thomas Bouch
Thomas Bouch
Sir Thomas Bouch was a British railway engineer in Victorian Britain.He was born in Thursby, near Carlisle, Cumberland, England and lived in Edinburgh. He helped develop the caisson and the roll-on/roll-off train ferry. He worked initially for the North British Railway and helped design parts of...

, the engineer of the first bridge. They failed at about 20 tons tensile load rather than the specified 60 tons, and were a prime cause of the collapse of the bridge on 28 December 1879.

Since Kirkaldy tested several samples of each of the lower and upper lugs, he was able to show that they exhibited a range of strengths, the lowest results being caused by defects like blow holes in the cast metal. Thus some of the upper lugs were actually weaker than the strongest lower lugs, an observation confirmed by damage shown on the remains left on the piers after the disaster. He tested the wrought iron tie bars themselves, and they proved tough, as specified, although only slightly stronger than the cast iron lugs to which they were attached. The high girders were also made of wrought iron and had a very high tensile strength. They were found after the accident at the bottom of the Tay estuary and had sustained relatively little damage compared with the cast iron columns which supported them. Some were reused in local houses, and when they were demolished in the 1960s, some were removed to the Royal Museum of Scotland in Edinburgh, where they are on public display.

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