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Columbus Tunneling Contractor
Takes on the Tough Projects
By Desiree Willis
Ohio contractor Capitol Tunneling Inc. has been in
business for 50 years and is now setting new standards
for hard rock disc cutting heads. The company
has no less than three record-breaking projects, including a
recently completed 440-ft long sanitary sewer line in Cold
Springs, Ky. — a record for a Small Boring Unit (SBU-A) in
the 24-in. diameter range.
The third generation family-owned business began in
1960 and now employs about 50 people in nine crews
working in states east of the Mississippi. Capitol Tunneling’s
use of Robbins SBUs dates back to 1997, when the company
used one of the first models for a 345-ft long water line
extension under a freeway in Louisville. “We wanted to
compare disc cutter performance with standard roller cone
rock cutting,” said Capitol Tunneling president and CEO
Kyle Lucus, of his initial decision to try Robbins SBUs. “The
technology has since proven itself on over 50 successful
projects for the contractor in the last decade.”
Within the last year, Capitol Tunneling has completed
2,766 ft of bores using SBUs ranging in diameter from 24 to
72 in., including two landmark distances. Capitol is now
setting its sights on more records, including two ongoing
bores in Pennsylvania and Virginia. “These machines are an
advantage for us, because they are a dry process, not requiring
additives or slurry like other methods such as roller
cone heads and microtunneling. Because of this we don’t
The contractor used the
first-ever Robbins Motorized
SBU in 2006, on two sanitary
sewer tunnels in Ohio
have separation issues with spoils and can operate even in
the most environmentally sensitive areas,” said Kyle Lucus.
A History of Small Boring Units
Since first using the disc cutting heads in 1997, Capitol has
purchased five SBU-As and one SBU-M and has options to purchase
several more. The fleet is typically used on eight to 10 jobs
per year. “My father helped Robbins in the development process
on the 1997 project. They have always been willing to work with
us and listen to our suggestions to make the product stronger,”
said Noah Lucus, project manager and estimator for Capitol.
In 2006, the company purchased one of the first Robbins
Motorized SBUs for a gravity sewer project in Ohio. The
Perry Taggart Sanitary Sewer called for five crossings
including two long crossings of 425 and 450 ft, which were
originally specified as microtunneling. Capitol instead won
the bid and successfully excavated the crossings using the
60-in. SBU-M/ABM setup, which remains a part of its fleet.
For Capitol, the setup of an ABM paired with a hard rock
disc cutting head fills a specific need, particularly on long
crossings in hard rock. “We have used roller cone heads, flat
face rock heads and bullet bit heads. Each has its intended
use, but the harder the rock, the more efficient it becomes
to use a disc cutting head,” said Kyle Lucus.
General superintendent Dave McCulloch, who has worked
on multiple SBU projects over the years, adds to the senti-
40 TRENCHLESS TECHNOLOGY February 2011 www.trenchlessonline.com