June 2012 note: A 3-D laser scan recently performed by Andrew Torgeson of Surface and Edge, www.surfaceandedge.com, contributed to Friends of Morden Mine free of charge as a public service, shows present state of degradation of Morden Colliery's structures quite well. See http://vimeo.com/42980569.
Colours and shades are inherent with the technology, but have no meaning. Transparent surfaces and missing columns and beams indicates that the scanner could not reach those surfaces. Hopefully, at some future time a scan can be done again when there is a man lift available, so that additional surfaces can be scanned for a more complete picture.
2013 Update to 2007 Review of Morden Colliery's Structures
As of 2013, the structures at the Morden Mine site are now 100 years old. The deterioration of concrete components of the headframe and the tipple structures is escalating at an alarming rate. Every spring more dislodged chunks of concrete can be found on the ground below the structures and more reinforcing steel becomes exposed to the elements.
Cost estimates for the restoration of these structures have escalated at an alarming rate as well. In 2007, a $100,000 sum of money was considered a good start to stabilize the most vulnerable sections of the tipple structure; the current estimate obtained from a restoration contractor projected $250,000 to $500,000 figures for emergency repairs. This is a direct result of the ongoing dilapidation of the exposed concrete structures and somewhat the ever inflationary cost of construction.
The need for restoration work has never been more urgent to avoid a catastrophic collapse of the heritage structures at the Morden Mine site.
Structures of the Morden Mine Colliery
By John Hofman, P. Eng. FOMM Member
At the start of the year 2007, several spectacular concrete structures still exist at this former mining site that dates back to the era of coal mining in the Nanaimo region. Unfortunately, sustained exposure to the elements for a period of approximately 90 years, without any or little maintenance has taken its toll on the capability of the concrete elements of these structures.
Repairs to the concrete elements of the head frame and the tipple are urgently required to maintain the stability of these structures.
In this context, "maintaining stability" implies that part of the tipple structure could collapse on its own from gravity loads, if the supporting columns are not repaired. From the public parking lot a visitor to this facility may notice that the concrete at the base of the columns, located just inside the fence, has disappeared; only some rusted steel bars remain. A collapse of this end-bay of the tipple supported by these columns is imminent, unless these columns are repaired or temporarily shored. Similarly, continued deterioration of constituent materials may result in irrecoverable damage as a result of partial or total collapse of significant sections of the tipple.
The head frame is comprised of a number of vertical sloping elements that converge at the top and that rely on a system of horizontal tie beams for lateral support. Porous materials such as concrete will absorb water. Freezing and thawing action of this water that becomes trapped in the pores, crevices and cracks of the concrete mass exerts stresses and strains, that will dislocate the material bit by bit over time. This results in cracking, crumbling and spalling of concrete, visible throughout this lattice work of beams and columns of the headframe. A visitor walking from the parking lot around the fence to the other side will see a close up of the results of this destructive process. Much of the reinforcing steel is exposed where concrete has disappeared and many pieces of concrete that fell down over the years are scattered about in the grass below the headframe.
Because of its size and shape the headframe structure may appear invincible, but is in fact quite fragile. If the tie-beams in this type of structure cease to provide lateral support, the vertical elements would buckle sideways. This could result in a sudden collapse of a substantial portion or a total destruction of the head frame, probably beyond any means of recuperating the authentic features of this mining monument. Although one of the horizontal tie-beams collapsed during the winter of 2005/2006, fortunately no further damage was sustained in that incident at that time.
Some local and/or overall repairs or temporary shoring is urgently required to keep this structure standing. Initial repairs would be aimed at the preservation of the concrete, so that it would be more capable to resist the deterioration processes and maintain the structural integrity to support gravity and wind loads. Funds in the order of $50,000 to $100,000 would probably go a long way towards repairs to the columns and the slabs of the tipple structure. The height and size of the headframe demands more extensive shoring to ensure the safety of the workman and to facilitate construction sequencing of the remedial work. The probable cost of initial retrofit work to restore the structural integrity of the headframe and to obtain an acceptable level of durability of the concrete may be in excess of $500,000.
The Friends of the Morden Mine Society (FOMM) have spent a significant amount of their limited financial resources on several engineering reports that describe the condition of the structures and provide recommendations for retrofit work and temporary shoring. Copies of these reports are available on request to anyone who is interested at the cost of reproduction or printing of these documents.
Please contact FOMM for further information or for input that one has to offer on the structural/material issues of the physical facilities at the Morden Collieries as these exist today.
(Friends of the Morden Mine thanks Robinson Rentals of Nanaimo for supplying the man-lift free of charge to assess the damage to the structures.)