From:
Re:
C. Motion:
Discussion:
City of Nashua, Public Works Division
Board of Public Works Meeting Date: February 8, 2018
Stephen Dookran, P.E., City Engineer
Engineering Department
Temple St Guardrail
To approve the contract for an amount not to exceed $120,000 to William P.
Davis Excavation, LLC for the installation of guardrail on Temple Street.
Funding will be through Department: 160 Engineering; Fund: Grant; Activity:
Highway Block Grant.
On the north side of Temple St between Amory St and Spruce St, the road is
separated from Pan Am’s railroad tracks by a retaining wall that has a drop of
about 8 feet in places. The existing 1,100 linear feet of chain link fence
protecting against that hazard was installed (circa 1999) by the City after the RR’s
own fence located on top of the retaining wall was determined to be in a
dilapidated condition.
The existing fence itself is now in a deteriorated condition and needs to be
replaced. The Engineering Department has recommended that the replacement
needs to be a guardrail to provide the proper roadside protection to motorists
because of the large drop to the RR tracks and a vehicle had driven through the
fence several years ago. However, installing the 6-ft deep posts to install the
guardrail is difficult with the large Fairpoint Communications underground duct
banks in the way. DPW has reached out to a number of contractors for quotes to
perform the work in a safe and cost effective manner.
The typical guardrail contractors are not interested because of the difficulties in
dealing with the duct banks. However, William P. Davis Excavation has
submitted a proposal to vacuum excavate the post holes in lieu of driving
(hammering) the posts into the ground which is the typical installation method.
Vacuum excavation is digging by using a vacuum to break apart underground
material using high pressure air or water. This method is also known as “Soft
Dig” and is considered safer than hand digging within the tolerance zone around
underground utilities.
At this time, only a preliminary design has been completed since changes to the
layout are expected as the exact location of the ducts and vaults will be found
during the excavation process. We are seeking a contract approval for an amount
not-to-exceed $120,000 which will hopefully cover the unknown conditions.
William P. Davis Excavation, LLC has successfully completed a number of
wastewater related projects for the City and comes highly recommended.
