ADMINISTRATIVE REPORT

Date: July 9, 2002
Author/Local: T. Ban/323-7782

RTS No. 2703

CC File No. 1501

Council: July 23, 2002

TO:	Vancouver City Council
FROM:	General Manager of Engineering Services
SUBJECT:	Purchase of Metal Shoring

RECOMMENDATION

THAT Council approve the allocation of $400,000 from the Truck Plant Account for the purchase of metal shoring to be funded from internal rates with no increase to the Operating Budget.

POLICY

Council approves expenditures from Reserves, including the Truck Plant Account.

Council approves all increases in service levels including the addition of trucks and equipment to the fleet.

BACKGROUND

The Sewer Operations Branch routinely excavates large quantities of soil throughout the City in order to gain access to and repair sewer lines. At virtually all project sites, heavy-duty earth-moving machines dig trenches at various depths to gain access to these sewer lines. Unless these freshly dug trenches are supported by a shoring system, they will collapse. A typical shoring system consists of at least two wood or metal wall sections and several supporting struts. Wood shoring is completely hand-built by construction crews whereas metal shoring is prefabricated.

DISCUSSION

Currently, the City uses a mixture of wood shoring and combined metal/wood shoring. Wood shoring easily lends itself to customization, particularly when there are spatial conflicts with underground water, sewer, gas, and electrical lines. However, when long sections of trench wall need to be quickly supported, wood shoring is not the best choice. Wood shoring cannot be quickly assembled or disassembled, nor be easily moved. Often, a whole team of construction workers is needed to load and install the wood shoring system. Such jobs are shored more quickly and efficiently with combined metal/wood shoring than with wood shoring alone.

The Sewers Operations Branch recently finished a 12 month trial implementation of various types of prefabricated metal shoring in conjunction with wood shoring. By the end of the trial, the Sewers Operations Branch observed several direct advantages of the combined metal/wood shoring system over wood shoring including fewer man hours lost per year to WCB claims and a corresponding increase in productivity. The Sewers Operations Branch also concluded that the combined metal/wood shoring system could be effectively utilized in the majority of the City's current and future sewer installation projects.

FINANCIAL IMPLICATIONS

There will be a one time charge to the Truck Plant Account of $400,000 for the Sewers Operations Branch, which will be repaid over the economic life of the equipment via a rental charge of $65,000 per year.

From the years 1996 to 2000, the Sewer Operations Branch exclusively used wood shoring at an average total yearly cost of $470,000 (including WCB costs). In 2001, the Sewers Operations Branch started using rented metal shoring as well as wood shoring. This change lowered lumber costs by over 80% from the previous year. By owning instead of renting the metal shoring systems, a further savings of $155,000 per year can be achieved (see Table 1). Therefore, the least expensive choice for shoring was demonstrated to be owning a combined metal/wood shoring system.

Additional savings can also be achieved through a reduction of WCB claims. Currently, there are over 5,400 man hours lost per year while solely using wood shoring. Conversely, WCB claims for combined metal/wood shoring are only 2,750 man hours lost per year, or $75,000 per year. There are also secondary savings predicted in the form of lowered expenses (WCB surcharges, rehabilitation costs, and medical expenses). These are significant costs, but are hard to accurately quantify. Therefore, the net savings between the various options are conservatively estimated at $155,000 and $230,000.

In addition, the use of metal shoring in conjunction with wood shoring also complements the City's policy on sustainability by reducing the amount of lumber used for shoring work.

Table 1 compares the costs involved to rent or own a metal/wood shoring system with an 100% wood shoring system.

Table 1: Detailed Yearly Costs

		Proposed	Trial	Previous
	Costs and Charges	Owned Metal Shoring & Wood Shoring	Rented Metal Shoring & Wood Shoring	Wood Shoring
A.1	Internal Rate Charges	$65,000	n/a	N/a
A.2	Equipment Rental Costs	n/a	$220,000	N/a
A.3	Shoring Maintenance	$40,000	$40,000	N/a
A.4	WCB Costs	$75,000	$75,000	$150,000
A.5	Lumber Costs	$60,000	$60,000	$320,000
Total Yearly Costs		$240,000	$395,000	$470,000

_ _

Net Savings $155,000

_ _

Net Savings $230,000

RECOMMENDATION

We recommend approving the purchase of $400,000 in metal shoring from the Truck Plant Account for the Sewers Operations Branch. This will enable the City of Vancouver to acquire 44 aluminum trench shields, 12 steel trench shields, and 12 sets of multi-shore systems and all associated components.

This purchase will be funded from internal rates with no increase to the Operating Budget.

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(c) 1998 City of Vancouver