Snorkel MHP 13/35 Mark II, Maintenance And Repair Parts Manual

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Stability Testing MHP15/44
❑
Introduction
The purpose of this test is to assess if the MHP 1544
meets the requirements of AS 1418-10 2004
Appendix G Stability Calculations. The situation for
minimum stability is with the booms at maximum
outreach over the drawbar, with the maximum rated
load in the platform, a manual force pulling toward
the drawbar and maximum wind load acting on the
back of the machine.
Since this testing involves taking the machine to the
edge of its stability envelope care must be taken to
ensure the test is failsafe i.e. the machine can not tip
over if it fails the test. To this end the rated load is to
be hung from the Test Weight Harness and the test
weight is suspended 200mm above the ground
during the test. If the machine starts to tip over the
test weight will contact the ground, reducing the
overturning moment, so that the machine can not
continue to tip over.
❑
Equipment
●
MHP 15/44
●
Spirit level
●
Rope
●
Pulley
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Test weights & harness
●
Ratchet tie down
❑
Setup and Procedure
The Test Weight harness location is at the rear edge
of the platform. The test load for a standard machine
is 220kg and the test load for a machine with an
optional basket rotator is 194kg.
The manual force is 400N with an additional
multiplication factor of 1.1 giving 440N or 45kg. The
line of action of this force is such that it produces the
greatest overturning moment. That is the line of
action of the force is perpendicular to a line joining
the top rail of the platform to the tipping line (see
Figure 1).
The wind load is assumed to act at the centre of area
of the elevated components. The Wind Load is 336N
at 5.54m above ground. The overturning moment
from the wind is used to find an equivalent force
along the line of action of the manual force. The
calculated force due to wind is 248N or 27.2kg
The load simulating the wind and manual force is
therefore 72.2kg.
The test procedure is as follows (Refer Figure 2).
1. Set a pulley with rope, 6.85m above the
ground on a fixed pole.
2. Place the machine so that the drawbar is
pointing towards the fixed pole. The centre
of the slew bearing must be 8.2m from a
point directly beneath the pulley.
3. Raise the machine on the stabilisers to
maximum height.
4. Level the machine laterally using the spirit
level.
5. Level the machine fore and aft such that it is
0.5 deg drawbar down from level. (This
simulates a poor setup by the end user).
6. Slew the booms until the rear of the basket is
pointing towards the pole.
7. Tie the rope from the pulley around the top
rail of the platform on the basket centre line.
8. Attach the Test Weight Harness and the Test
Weight to the platform.
9. Raise the booms to maximum outreach
(lower boom fully up and top boom and jib
boomhorizontal). The Test load must be
between 100 and 200mm above ground.
10. Attach a ratchet tie down to the rope coming
from pulley. Attach the other end to the Load
simulating the wind and manual force.
11. Raise the Load simulating the wind and
manual force with the ratchet tie down until
the load is between 100 and 200mm above
the ground. Ensure that the loads are not
swinging i.e. the loads are static. (If both
‘rear’ legs lift clear of the ground STOP the
test and release the ratchet).
❑
Pass Criteria
The machine can be assessed as meeting the
requirements of AS 1418-10 2004 Appendix G
Stability Calculations if the Test Load and the Load
simulating the wind and manual force can be raised
c l e a r o f t h e g r o u n d s i m u l t a n e o u s l y w h i l e
maintaining at least 3 point contact i.e. not more
than 1 stabiliser foot off the ground.
page xxii Rev D MHP13/35 & MHP15/44 Mark II – 12785B
Maintenance Information