TAP & DRILL METHOD

We have developed a universally applicable method that a foundry can use to drill and tap the receptical into a manhole frame on a one-at-a-time basis.  This same method can also be used to drill and tap the Armstrongs Mutli-Positional Handholds receptical into onsite manhole frames where the frames have already been set to finished elevation.  Threading the "T" Bolt into the receptical completes the handhold.

The following videos will provide an example of the Tap & Drill method:

Armstrongs Multi-Positional Handholds has developed a handhold which can be incorporated into a municipal manhole frame to be used by workers entering or exiting a manhole.  Armstrongs Multi-Positional Handholds (AMPH) will soon be making available manhole frames with the AMPH receptacle incorporated into its cover support flange, requiring only the simple procedure of threading the handhold into the receptacle to complete the handhold.  These frames will soon be made available through local distributors.

We invite you to offer your comments or ask questions regarding the Armstrongs Multi-Positional Handholds device through our "Contact" page.  

Engineered drawings

To view drawings

INTERTEK Report

For technical information found in the Report of Modified Manhole Frames tested in accordance with AASHTO M306-10, Drainage, Sewer, Utility, and Related Castings with reference to H-25 loading requirements 

Worksafe BC OHS ASTM C478M

Section 13.2(1) of the OHS Regulation states.... 

Tests & Certification

H25 loading test results:  Intertek Testing Services NA Ltd.  Testing done by Intertek on three different manhole frames where multiple holes were drilled in the frame, in multiple configurations and showed no diminishment in the frames H25 loading capacity.

ASTM C478M:  The Multi-positional Handhold complies with ASTM C478M, provision of a handhold, which allows the distance to the first step/rung in the manhole to be extended from a maximum of 20" to a maximum of 26" when the Multi-positional handhold is incorporated into the manhole frame.

OHS Regulations cited:  relevant to the manufacture and installation of the Multi-positional handhold into its workplace application.

OHS regulation 4.3 Safe machinery and equipment; (1)(a) capable of performing the functions for which it is used.  (1)(b)(i) Operated in accordance with the manufacturer's instructions.  (2)(b) As specified by a professional engineer.

The Manufacturer's drawings of the Multi-positional Handhold contain complete instructions and the drawings have been certified by a structural engineer, confirming compliance with the above cited OHS Regulations.

ARMSTRONGS multi-positional handholdS

Patent No:  US 9,845,586  -  US 10,030,350 -  US 10,030,351 - US 10,030,352 - CDN 2,915,957

FIELD SCENARIO

Typical Field Scenario:

Manhole Frame Height               =  7"

Distance from top of concrete

manhole lid to the step/rung in

the lid                                          =  4"

                                                   = 11"

With the maximum allowable distance of 20" to the first step/rung in the manhole 9" of space is available for the adjustment of the manhole frame to achieve final slope and elevation.  Beyond 20" it is typical to install a step/rung in the concrete support structure of the frame, with the Armstrongs Multi-Positional Handholds incorporated in the manhole frame the provision of a handhold is met (as per ASTM C478M) and the distance to the first step/rung in the manhole may now be extended from 20" to 26".  The additional 6" of adjustment space brings the adjustment space total allowable to 15".  Beyond this distance should 16" of adjustment space be required, you are now able to add a 1' manhole barrel section and you will still have an adjustment space of 4" beneath the manhole frame.

Note: the addition of a step/rung into the concrete support area of the frame will typically reduce the clearance in the area across from the step/rung from 25" to 19".  Ask any work entering or exiting a manhole if he doesn't appreciate the added clearance in this area as afforded by the incorporation of a Multi-Positional Handhold into the manhole frame and the elimination of the step/rung in this area.