Since it`s completion in 2003 “The Spire” has caused a lot of debate among Irish people, some love it while othes are not so keen on it. Love it or hate it you can`t help being impressed by its sheer scale as you approach it. I had it in mind to visit it one evening as darkness approached to get some light trail shots around it and maybe some reflections in the polished lower section so I set off last Sunday evening with that intention. When I got there I realised that it was going to be bright for quite a while so I decided I would try my usual 3 exposure HDR shots until the light started to fade. By the time the light was low enough for me to take some long exposures it was nearly time for me to go but I was pleased with what I got.
Here are some of the images and I have included some information that I found on the net.
The Spire of Dublin, a 120 metre high landmark in the heart of Dublin City, was unveiled in 2002.
The huge, striking, and innovative monument stands in the middle of O’Connell Street just across from the famous General Post Office. During daylight, the light of Ireland’s sky over Dublin, the streetscape and its people is softly reflected in the stainless steel surface of the Spire.
From its base up to about 10m, the stainless steel is partially polished in an abstract design to provide a slightly higher reflective surface than the remainder of the Spire.
From dusk, the Spire’s stainless steel surface is softly lit by the ambient lighting of the streetscape. The base is gently lit and the tip illuminated from a light source within to provide a beacon in the night sky over Dublin. The Spire has its roots in the ground and its light in the sky.
120 metres high and 3 metres in diameter at the base, the Spire rises above O’Connell Street, breaking above the roof line with as slender and elegant a movement as is technically possible. It is approximately 15 centimetres in diameter at its apex.
The upper part of the Spire sways gently when the wind blows, reflecting the character of the citys climate. The monument’s tip can sway up to a maximum of 1.5m under extreme wind loading – don’t be too alarmed if you’re nearby when this happens, all tall slender structures move in the wind, even lamp posts!
Spire of Dublin Facts:
Height: 120 metres (7 times height of the General Post Office)
Diameter at base: 3 metres
Diameter at top: 15 centimetres (6 inches)
Weight: 126 tonnes
Shape: hollow cone
Thickness of steel plate: varies from 10mm to 35mm (thickest at base)
Number of bolts: 204
Number of drilled perforations in top 12 metres: 11,884 (diameter of hole 15mm)
Length of weld: 540 metres approx.
Number of concrete foundation piles: 9
The Spire signaled the start of the reconstruction of a new public domain for O’Connell Street which has see the creation of a new plaza at the General Post Office, a new tree lined boulevard and kiosks along the street. (Courtesy of www.visitdublin.com)
Click on any image to enlarge it.
The contract to build the worlds largest monument The Spire of Dublin was awarded to Radley/SIAC JV in February 2002. The two companies set up a joint venture to build and erect The Spire. SIAC responsibility was for the civil works and Radley’s was the fabrication and erection.
The first task was to order all the materials necessary to fabricate The Spire. Various manufacturers were assessed to establish their suitability and capability to provide the materials and services required. The stainless steel plates were procured in France. The plates were produced with blemish free surfaces to enable us to build The Spire to the Architects high specification. The plates used in the first 4.1 meters were 35mm thick and then from 4.1 to 112 meters the thickness was 20mm and the rest up to 121.2 meters was 15mm thick.
The plates required for the 44 individual sections of The Spire were developed using a special computer programme. The mill were given these sizes with tolerances of + or – 2mm on the length and width. These plates were rolled at the mill as a special order to ensure that no surface defects whatsoever occurred during the process.
The sections, each of which were approximately 2.8 metres high, starting at a diameter of 3 metres at the base were rolled until the diameter of The Spire reduced to 700mm after which the plates were press braked. Each section was rolled in two halves with a green area of 250mm to ensure that after rolling or pressing each section was perfectly round.
The main jointing flanges were forged in Germany by Bruck AG. They took ingots off grade 1.4401 316L stainless steel, heated them in special furnaces and then worked them into shape whilst they were hot. Each set of flanges were forged as a pair and then split, stress relieved, machined and match drilled to the drawings supplied by Radley Engineering working to tolerances of plus or minus of 0.5 of a millimeter over 3 meters diameter. The outside of the flanges were machined to the exact taper of The Spire. This ensured that when the plates were welded to the flanges they were a perfect match.
Because of its great height (121.2 meters) The Spire required a Tuned Mass Dampening System to prevent fatigue. Motioneering Inc of Canada designed the TMD system that is the first of its kind to be used in Ireland as this sort of system is generally used in tall buildings. The system consists of two hollow tube dampers. These are suspended from stainless steel wire ropes 76 meters high inside The Spire. The technology used in the design of the TMD system is similar to that being used in the construction of one of the world’s tallest buildings, The Taiwan Tower.
Whilst all this work was being carried out welding procedures were being developed at our workshop in preparation for the arrival of the plates. Test plates to suit the individual thickness were prepared and welded. These were mechanically tested to BSEN 288-3. At the top end of The Spire where the diameter decreased below 500mm and it was not possible to use a double operator procedure we developed a procedure for single sided class E welds. On completion all welds were strip polished, 100% X-rayed and Dye-Penetrant Tested. Test plates were then shot peened to the finish of The Spire and sent to Corus Laboratories in Sheffield for salt spray testing. The salt spray test lasted 21 days and after analysis it was accepted that the plate finish and the welding would be sufficient to withstand the atmospheric conditions in Dublin for the next 120 years at least.
With all the testing complete the plate sections were then ready for cutting and welding. The two halves were joined together and welded. Then starting with the top flange each section was joined together to make up individual Frusta. There were a total of eight Frusta consisting of 44 sections to make up the entire height of The Spire. The ninth Frusta is the aviation light housing which is an open section. This was manufactured from individual sections. After completion of NDT all welds were polished and then the entire Spire was polished again and again to remove “stretch marks” which had appeared during forming. To achieve this finish polishing machines were custom built with special tracks to run up and down the length of each section. The Spire sections were being rotated at the same time on extensions bolted to each end so that there would be no contact on the polish surface at anytime.
On completion of polishing each section was brought into a specially constructed building for shot peening . This was done using a specially constructed multi head shot peening machine that ran on tracks 25 meters long. This machine required a 1000 CFM Compressor to hurtle 1 tonne of 3/32 diameter stainless steel balls at the surface of The Spire every 10 minutes. Each section had to be Peened four times to achieve the correct coverage. The Spire for the whole of this time was constantly rotated using the same extensions at each end that were used for polishing each section. On completion the surface of The Spire was inspected to ensure that the impact coverage of the ball bearings was between 98% and 120%. The Spire was then cleaned, wrapped and transported to Dublin.
The Spire sections were shipped to Dublin on special telescopic rear axle steering trailers. Each section as it arrived in Dublin was unloaded using McNally Crane Hire’s 1000 tonne crane, the largest of it’s kind in Europe, and a 100 tonne tailing crane. The first section was hoisted into the vertical then lowered down over 48 M60 by 850mm long super duplex bolts that had been previously cast into the concrete foundations. To ensure a perfect fit a specially constructed jig had been used to hold the bolts in place whilst the concrete was being poured. The nuts were then fitted to the bolts and tightened. Each of the remaining sections were joined and tightened to their relevant pre-tension values at each flange. Each bolt has in place a system to check that the tension is being maintained. A specialist sub-contractor under Radley Engineering supervision undertook the erection.
The fabrication and erection of the Spire was completed without any accident or incident. This was achieved by careful attention to detail by all involved and was coordinated by Radley Engineering’s Safety Manager.
The finishing touch to The Spire is a pattern that has been shot peened for the first 10 meters onto a mirror polish surface using a special masking stencil that could withstand the impact of the stainless steel balls. The pattern is a reproduction of a core that was drilled under the location of The Spire. The pattern of the core was copied and digitally reproduced on a disc that was fed into a plotting machine to cut the exact pattern.
For internal maintenance a ladder system is installed from the bottom of the chamber through the top of the fifth section and stops at the 76 meter point. Because of room restriction there could be no backing hoops on the ladder for safety so a special arrest system was installed in the center of the ladder and as the steeplejacks climb the ladder they hook into this system. The ladder was also used to access each level during erection and bolting. Running alongside the ladder is a cable tray and internal lighting. A 4” rainwater drain pipe runs from a gutter at the top of The Spire to catch the water coming through the holes for the Architectural lighting.
The eighth section of The Spire has 11,692 15mm holes drilled in it to allow the light from the architectural lighting, which will be fitted internally along with the aviation lighting, to shine through. The lighting system is fitted on a special raise and lower system. The light units themselves are LED’s which are made up of seven individual tubes with hundreds of individual lights. The whole unit can be lowered to the bottom of The Spire and the sections changed and raised to the top using a motorised winch.
Some Spire Facts
- Height – One hundred twenty one metres. (396 Feet)
- Weight – One hundred thirty tonne (128 Tons)
- Length of Weld – Three kilometres (2 Miles approx.)
- Surface Area – Five hundred sixty square metres (6017 Sq.Ft.)
- No. of X-Rays – Two Thousand
- Manufacturing Time – Five months
- Sway at the top is 1.5 Metres in any direction.
- There are 48 M60 hold down bolts.
(Courtesy of Radley Engineering)