Newmont Mining Corporation - Waihi Gold: Pumphouse Relocation

Waihi's historic Cornish Pumphouse was ‘on the move’ in 2006!

The Cornish Pumphouse was built in 1904 to house steam-driven pumping machinery to dewater the underground Martha Mine that operated from the 1880s to 1952. The steam machinery was used until 1914, when it was replaced by electricity. During the 1930s the machinery was stripped out and the building became derelict.

Historic underground mine workings threatened the stability of ground beneath the pumphouse and investigations from 2004 concluded that the only way to protect the historic building was to relocate it to a safe site. In 2006 internal bracing was installed to strengthen the structure and earthworks were carried out to construct the relocation causeway.

In an acclaimed feat of engineering, this iconic building – weighing 1840 tonnes and standing three storeys high, was moved in its entirety to its present site during the third quarter of 2006. It was shifted on teflon-coated concrete beams to a new site 300 metres away.

Follow progress of this massive feat of engineering as it unfolded in the photo diary below...

		The Cornish Pumphouse was built around 1904 to house steam-driven pumping machinery needed to dewater the mine.The pump was used until 1913 and kept in working order until 1929. After this it was abandoned, the machinery removed and the steel beams inside removed for scrap. photo taken about 1950

		In 1961 the collar of No. 5 shaft west of the pumphouse collapsed leaving the structure on the edge of a potentially dangerous void.

		This aerial photograph taken from the south in the mid 1980s shows the collapsed No.5 shaft on the left (west) of the picture.

		In 1987 Waihi Gold Mining Company fenced the area around No.5 shaft for public safety. Construction of Martha Mine had begun and a viewing platform was placed next to the pumphouse. Paths were constructed and the area planted with native trees and shrubs.

		With the town's Information Centre and the Martha Mine Education Centre operating close to the pumphouse the area further developed as a significant tourist attraction.

		The autumn colouring of the Virginia Creeper accentuates what had become a tourist icon.

		By 1995 regular monitoring of the building and surrounding area by Waihi Gold Mining Company showed that the pumphouse was slowly tilting, and that the ground on which it was built was also moving.

		In 1999 access to the pumphouse was restricted following a series of nearby ground subsidences and the increased danger of a similar subsidence of No.5 shaft immediately adjacent to the structure.

		By the beginning of 2005 it was obvious that the pumphouse was tilting dangerously and the ground on which it sat was continuing to move. Experts advised that if it was to be saved the building itself would have to be moved. All interested parties met to consider the future of the structure. In June 2005 conservation architects responsible for moving the Museum Hotel in Wellington got a close look at the condition of the 100 year-old structure

		June 2005 A 100 tonne capacity crane is brought on site to secure the weight of a small drill rig above the partially collapsed No.5 shaft. The rig drilled into the shaft to investigate ground conditions.

		June 2005 A flat rack container platform supports the small drill rig above the partially filled No. 5 shaft. The platform is suspended from the crane. Staff wear fall arrest equipment attached to a rail above the platform.

		June 2005 A large range of possible relocation sites and transport routes was considered. A geoprobe vehicle investigated the condition of the ground along which the pumphouse may travel. This information provided allowed geologists to determine how much preparation each section of the route would require.

		December 2005 Scaffolding was installed inside the pumphouse ready for detailed investigations of the structure and the installation of internal steel beams to brace the building.

		A final site and relocation route was determined. The pumphouse will first move south (to the left of the picture) and then travel west along the tree line towards the top right of this photograph.

		January 2006 Pine trees along the selected transport route were removed.

		30 January 2006 All trees and undergrowth removed. The site was ready for earthworks to commence once archaeological inspections were complete.

		31 January 2006 Upper level steel work was welded at Mount Maunganui Engineering's workshop.

		31 January 2006 Lower level beams were completed at Mount Maunganui and transported to Waihi.

		2 February 2006 Consulting archaeologist Ray Hooker unearthes a bottle dump just west of the pumphouse.

		12 February 2006 Members of Historic Places Trust study a small selection of the artifacts collected. All artifacts were catalogued and recorded. Over a period of two weeks over 250 people took advantage of the opportunity to take guided tours of the site and see the pumphouse close up for the first time in many years.

		The condition of the structure was regularly photographed and logged.

		14 February 2006 Lower level beams were welded into place.

		23 February 2006 Upper level steelwork was bolted into place. These beams provided the internal support for the shell of the structure during the move and remain in place in the new location.

		3 March 2006 Weak ground to the south of the pumphouse was removed to reveal the building's original foundations. Underdrains were installed in the area and then it was refilled with competent material capable of supporting the pumphouse for its 'step out' 26.5 metres to the south before beginning its journey approximately 300 metres west to its new home.

		3 March 2006 The original pumphouse foundations. Five foundation shafts were dug, timbered and then filled with concrete to provide the base on which to build the pumphouse. Some of the original timbers can be seen. The pumphouse was cut from these foundations just above the timbers.

		12 March 2006 Preparations continued on the route the pumphouse will take. Several weeks of fine weather mean the project is progressing well.

		13 March 2006 Rafters were lifted into place from the north side. On the skyline the pumphouse now looked the same as it did over fifty years ago in the photo at the top of this page.

		14 March 2006 With the rafters in place the steelwork paint was given a final touch up and the upper level of the scaffolding was removed.

		14 March 2006 Looking as good as new. Rafters, steelwork and beams were all modeled on the originals to preserve the integrity of the building.

		23 March 2006 The ground level to the south of the pumphouse was built back up to its original level using material capable of holding the weight of the building during its move.

		24 March 2006 Attendees at the 2006 Annual Miners' Reunion got a close up view of activities on site.

		5 April 2006 Preload was added to the south of the pumphouse. This material acted as a weight to compress the ground ready for the move. It was removed after measurements confirmed that the route had been compressed sufficiently to hold the almost 2000 tonne weight of the building during transportation.

		13 April 2006 The pumphouse was illuminated as part of Waihi's celebration of 100 Years of Rail over Easter weekend. Preload material is silhouetted in the lower foreground.

		21 April 2006 With scaffolding removed from the lower level a small excavator was used inside the pumphouse to remove soil and debris from the lower floor under the watchful eye of archaeologist Ray Hooker.