Orinda, California, 1 November 2005 1

DATE: 1 November 2005

CLIENT: McNamara & Smallman, Livermore, CA

LOCATION: Cresta Blanca, Orinda, CA

JOB: 110' sewer replacement, hillside easement, from manhole in street to top of property line, pull upstream, 6" VCP to 6" PE

TOOLS: BC60 ram, 6" TRIC bursting head and core adapted to 1" swaged cable, PowerTeam 20HP high-pressure pump with hose

and control extensions

Technical Archives

Orinda, California, 1 November 2005 2

Pulling (exit) pit, at top of residential property line, about 4 feet deep in northwest corner of yard.

Orinda, California, 1 November 2005 3

Modifi ed 6” bursting head assembly ready for entry through back side of manhole.

Orinda, California, 1 November 2005 4

Back hoe assisting workers in keeping pipe away from building. Large 20hp hydraulic pump is in van.

Orinda, California, 1 November 2005 5

Checking progress of mole. Also, new sewer is crossing under a water main adjacent to manhole.

Orinda, California, 1 November 2005 6

Mole slides down cable into manhole, and now awaits core assembly as cable continues to travel. Entry should be monitored at this point to assure proper engagement of core with bursting head, before the

head is driven into the earth. Note excavations at 6” inlet (right) and opposite wall (left) large enough to accommodate bursting head.

Orinda, California, 1 November 2005 7

Extensions for hoses and control unit are required to reach 20hp hydraulic pump in driveway below. High pressures are expected, as ground in the area is dry and hard. Water is introduced to the line to submerge the bursting head downstream. Resulting pres-

sures achieved with TRIC BC60 ram are in the 2,000–2,500 psi range, equating to only about 12 to 15 tons of pulling force.

Orinda, California, 1 November 2005 8

Progress point: 3” cast iron tie-in from neighbor’s yard. Connection is broken away to reveal cable and water in easement line (top left), submerged head approaching tie-in pit (top right), head breaking through clay line at pit (bottom left), and new sewer

pipe sliding past tie-in (bottom right). Pulling upstream into a full pipe greatly reduces pulling force required, often by half!

Orinda, California, 1 November 2005 9

With less force required to burst pipe, cribbing is easy and even a wet hole stays intact.

Orinda, California, 1 November 2005 10

End of the line. Amazingly enough, this job might have been pulled with the smallest TRIC ram (BC20) and a properly adjusted pump. The BC60 is appropriate for jobs in the 8” range, including upsizing 6” to 8” sewers.

Orinda, California, 1 November 2005 11

Another hydraulic power source for higher volume, lower pressure pullers.

Orinda, California, 1 November 2005 12

Such as this far less portable static puller!

Orinda, California, 1 November 2005 13

Grippers are sandwiched inside this massive assembly, using 1.125” standard wire rope.