Pinnacle’s Trench Stackers are strong enough to handle the pressure from unstable soil conditions and provide a safe space for workers and protect them from a trench collapse. Whether digging the foundation for a building or laying pipes or wires, manhole stackers ensure worker safety and play a major role in the prevention of cave-ins and injuries.
*Images may feature optional components. Variations between the images and the actual equipment do exist, primarily with appurtenance locations, sizes, and quantities.
|Model Number||Description||Knife/No Knife||Pipe Clearance||PSF/C-60||Weight|
|PMS4M-416-NK||4″ Double Wall Medium Duty||Non-Knife||N/A||3018/50||4140|
|PMS4M-420-NK||4″ Double Wall Medium Duty||Non-Knife||N/A||1012/16||4500|
|PMS6M-416-NK||6″ Double Wall Medium Duty||Non-Knife||N/A||2671/44||6480|
|PMS6M-420-NK||6″ Double Wall Medium Duty||Non-Knife||N/A||1667/27||6795|
Each of our steel trench boxes comes with professional engineer certified and stamped tabulated data, which meets the OHSA 1926 Sub Part P Excavations standards
Frequently Asked Questions
Determine Correct Size
To determine the right size of stacker for your job answer the questions below.
Review the tables and information which accompany our specific products.
Always refer to manufacturer's serialized specific tabulated data and all applicable safety standards prior to each use.
What kind of job is it?
Sewer, repair, water main, manhole, pump station, bore pit, etc.
Depth of cut?
B-soils (45 lbs per foot of pressure)
C-60 soils (60 lbs per foot of pressure)
C-80 soils (80 lbs per foot of pressure)
Determine Spreader Length
If working with pipe, what is the outside diameter of the pipe?
Pinnacle recommends that the manhole box to be at least 12” wider than the pipe.
Determine Trench Shield Length
If working with pipe, what is the length of the pipe sections?
Pinnacle recommends that the manhole box be 2’ – 4’ longer than the pipe.
Determine Maximum Weight of Manhole Box System
Determine the working operation weight of excavator being used at job site and divide it by 5. This number would provide you with the maximum weight you excavator can handle.
When selecting box size the weight should include the spreaders.
Lay wall A of the stacker flat on the ground with the collars facing up as shown
Place each spreader on the collar one at a time as shown and insert pin and place keeper, make sure pin keeper in facing towards the bottom of shield as shown
Take wall B place over the top of the spreaders a shown and pin into place with keeper towards the bottom
Take your rigging place on top lifting eyes inside as shown and left to stand