The Great Gantry, Queen's Island, Belfast
005 • Sir William Arrol
In late 1908, the dream of the next generation of ocean liners moved from the drafting table to the real world. But Harland & Wolff realized that they did not have the necessary infrastructure to construct these giant ships and so they cleared the existing slipways and looked for an engineer capable of building a ground-breaking new gantry under which both ships could be built at the same time.
There was only one man for the job, the world renowned Sir William Arrol who had built the Tay Bridge, the Forth Rail Bridge and Tower Bridge consecutively.
Sir William Arrol was arguably the most celebrated engineer of the Victorian age. He was pioneering in his use of steel for construction and pushed the boundaries of bridge building, making him famous throughout the world.
Arrol had the ingenuity to implement engineer’s designs on a practical level, overcoming physical and environmental barriers to construction. He often came up with new techniques and inventions which would be subsequently be adopted as standard practice in industry, such as the hydraulic riveting machine, which not only sped up construction but produced a consistently stronger seal between the rivet and girder and improved safety.
The son of a weaver, he had to start work in the mills at the age of nine to help support his family. He started training as a blacksmith by age 13, and went on to learn mechanics and hydraulics at night school.
His characteristic drive and work ethic were evident throughout his life, first in educating himself, then walking the highways in search of work, competing for contracts for his new business, then striving to push his business into bigger and more technically challenging projects.
In 1863 he joined a company of bridge manufacturers in Glasgow, but by 1872 he had established his own business, the Dalmarnock Iron Works, in the east end of the city. The business evolved to become Sir William Arrol & Co.
When his company built the Forth Bridge, it was the first major structure to be built primarily of steel and the longest cantilever bridge in the world. After the disastrous collapse of the first Tay Bridge, Arrol was engaged to build the replacement bridge and restore the country’s faith in rail bridges. He quickly went on to build the steel superstructure of London’s iconic Tower Bridge, the largest bascule bridge of it’s time, and numerous other bridges in Britain and abroad.
Before the Gantry, the northern end of the Queen's Island shipyard had four building slipways, each with gantry cranes above them. The cranes formed three crosswise gantries over each slip, with jib cranes working from each upright.
To accommodate the massive new Olympic Class ships, Harland and Wolff converted three of their already huge slipways into two bigger slipways. No 1 slipway remained and continued in use, with its original gantries. The two new slipways were numbered 2 & 3. (Belfast’s taxpayers bore the cost of razing three existing slipways to the ground to extend the berthing piers by 100 feet.)
The new steel gantry was erected over the two new slipways, custom built to accommodate both ships simultaneously and meet the needs of such monstrous vessels. Four thousand tons of concrete were poured for the foundations. The gantry itself was 840 feet (260 m) long 270 feet (82 m) wide, with a height of 228 feet (69 m) to the top of the upper crane, and was constructed with over 6,000 tons of steel. In the middle were the world’s largest revolving cranes; on top were four traveling cranes and at the bottom there was five walking cranes at either side. There were also four elevators to take the men to their places of work.
The gantry was built on three rows, 120 feet (37 m) apart, of eleven steel truss towers with three large truss girders between them, and lighter crosswise Warren1 trusses above this. The large girders provided runways for a pair of 10-ton overhead cranes above each way and lighter 5-ton jib cranes from the sides. Along the center line ran a light Titan crane, with a reach of 135 feet and able to carry a 3-ton load at full radius, and 5 tons closer in.
The cranes were electrically-powered and built by Stothert & Pitt of Bath. Access to the high girders was provided by three long ramps and also electric lifts for the shipyard workers. As Harland and Wolff were primarily a commercial yard, there was no need for the huge Titan cranes being built at this time for the naval shipyards of the Clyde, where heavy lifts of armor plate, or even entire turrets, were needed.
By the end of that year, Harland and Wolff had built the tallest gantry ever that stood over the slipways known as the Arrol Gantry. And once the gantry was completed, Harland and Wolff started to hire shipworkers in record numbers.
The huge Olympic and Titanic structural silhouettes could be seen across most of Belfast City, shrouded by the even larger gantries in which they were constructed.
Olympic was the first keel plate laid beneath the gantry, and Lagan river behind the gantry and had to be dredged to 50 feet to accommodate the launch of these new super liners, and to support ships with a deeper draft.
The Arrol Gantry dominated Belfast’s skyline for many years and remained in use until the 1960's. Harland & Wolff had been in financial difficulties for decades and couldn't afford to keep it standing, so the structure was demolished in 1971.
In his autobiographical poem Carrickfergus2 the poet Louis MacNeice describes his birthplace: "I was born in Belfast between the mountain and the gantries, to the hooting of lost sirens and the clang of trams."
Without the Arrol Gantry, Olympic and Britannic would not have existed, and neither would the Titanic.
005.1 Reconstruction of North Yard slips 2 & 3 and erection of Arrol gantry for building OLYMPIC & TITANIC (400&401), 1907-1908. Photographer Robert John Welch (1859-1936).
005.2 Sir William Arrol, Scottish civil engineer, bridge builder, and Liberal Unionist Party politician, (February 13, 1839 - February 20, 1913). Arrol died at his home in Seafield, Ayr on 20th February 1913 at the age of 74 years. He had been suffering for about 5 weeks from flu which had developed into pneumonia and from which he was making a slow recovery. During this time, he developed an abscess in his lower bowel which required surgery, but in his weakened condition the operation was too much for his body to cope with and he died the following day. When he died Arrol’s estate was worth £317,749, today the equivalent of over £20 million.
Although he had no children of his own, Arrol was very much a family man and left bequests in his will not only to his immediate family but also to his extended family. He also left many public bequests including: Glasgow Royal Infirmary, Glasgow Western Infirmary, Ayr Infirmary, Glasgow Eye Infirmary, The Higginbotham Sick Poor Nursing Association incorporated Glasgow Old Man’s Friendly Society and Old Woman’s Home, and The University of Glasgow.
005.3 ‘Section of Gantry over Slips Nos 2 and 3’, The Shipbuilder, 1911. A gantry being a crane system that manoeuvres over the top of a ship in a dockyard carrying materials and workers.
005.4 Arrol Gantry under construction, 1907-1908. Photographer Robert John Welch (1859-1936).
005.5 Colored postcard showing ‘The Great Gantries’, Harland & Wolff shipyards, Belfast 1911.
005.6 RMS Titanic under construction in the Arrol Gantry. The "Chester" anchored in the foreground.
005.7 The Great Gantry under construction, Queens Island, Belfast.
Footnotes:
In structural engineering, a Warren truss or equilateral truss is a type of truss employing a weight-saving design based upon equilateral triangles. It is named after the British engineer James Warren, who patented it in 1848.
"Carrickfergus" is a 44-line poem by Louis MacNeice. It was written in 1937 and first published in book form in MacNeice's poetry collection The Earth Compels (1938). The poem reflects on MacNeice's childhood in Carrickfergus, a large town in County Antrim, Northern Ireland.