MEGA Corp. MHT175-CAT777-OPS-1 User Manual
MHT175-CAT777-OPS-1
SPECIALTY HAULAGE SOLUTIONS FOR CONSTRUCTION AND MINING
OPERATORS MANUAL
MEGA CORP.®
700 Osuna Rd. N.E. • Albuquerque, NM 87113 • 1-800-345-8889 • 505-345-2661 • Fax 505-345-6190
www.megacorpinc.com
® MEGA Corp., Inc. All Rights Reserved
MHT175-CAT777(G)-1
1 Aug 2012
TABLE OF CONTENTS
Page
Section 1. Definitions and Abbreviations …………………………………………………...…. 1-1
Section 2. System Descriptions ………………………………………………………….….… 2-1
Section 3. Normal Operations ………………………………………………………………..... 3-1
Section 4. Limitations …………………..…….……………………………………………...… 4-1
Section 5. Performance Loading .………………………………………………………………. 5-1
Section 6. Appendix ………………………………………………………………………….... 6-1
A
MHT175-CAT777(G)-1
1 Aug 2012
TABLE OF CONTENTS
B(Blank)
SECTION 1
Definitions and Abbreviations
Contents
Description ………………………….….… 1-1
Warnings, Cautions & Notes ……………... 1-1
Shall, Will & May ……………................... 1-1
DESCRIPTION
This technical manual contains information
required to safely operate the MHT175CAT777(G). See the CAT 777G Operations
and Safety manual for additional information
specific to the CAT 777G chassis.
WARNINGS, CAUTIONS AND
NOTES
The following definitions are found
throughout the manual and apply as follows:
Operating procedures and techniques, which
could result in personal injury and/or loss of
life if not carefully followed.
Operating procedures and techniques, which
could result in damage to equipment if not
carefully followed.
Operating procedures and techniques that are
considered essential to emphasis.
MHT175-CAT777(G)-1
1 Aug 2012
MHT175-CAT777(G) Overview ………… 1-2
Abbreviations ….……………………..… .. 1-3
USE OF SHALL, WILL AND MAY
Shall and Will – Used when application of a
procedure is mandatory.
Should – Used when application of a
procedure is recommended.
May - Used to indicate an acceptable or
suggested means of accomplishment.
1-1
MHT175-CAT777(G)-1
Top
3 7 3 4 4
Side
1
2
5
6 8 9
10
11
GOOSENECK
3
1
2
4
LOWER HOPPER
SIDE WALL
REAR BOGIE
6
HITCH & SADDLE
DECK & FENDER
TURN LIMIT INDICATOR
7 8 5
REAR AXLE & WHEEL GROUP
SPILL GUARD
SIDE BOARDS
9
10
END-OF-LOAD INDICATORS
11
MHT175 Overview
1 Aug 2012
SECTION 1
Definitions and Abbreviations
1-2
MHT175-CAT777(G)-1
1 Aug 2012
SECTION 1
Definitions and Abbreviations
ABBREVIATIONS
ft - feet
gpm – gallons per minute
kg – kilograms
km/h – kilometers per hour
lbs – pounds
MHT – MEGA Coal Hauler
MHT – MEGA Hauler with Truck
mph – miles per hour
psi - pounds per square inch
1-3
MHT175-CAT777(G)-1
1 Aug 2012
SECTION 1
Definitions and Abbreviations
1-4(Blank)
SECTION 2
System Description
Contents
Coal Hauler Body (MHT) ………...…..... 2-1
MHT Axle & Wheel Group ……............. 2-3
Hitch Deck & Fender ………………....... 2-3
MHT Brake System ……......................... 2-4
COAL HAULER BODY (MHT)
The MEGA 175 ton coal hauler is modular in
construction and comprised of four major sub
assemblies. The sub assemblies are the
gooseneck, lower hopper, side walls and the
rear bogie.
Gooseneck Assembly
The assembly is constructed of square steel
tubes, plates and channels. It contains an 18”
diameter hitch ball designed to be captured in
the tractor hitch socket allowing the trailer to
be towed. The compartment formed by the
gooseneck plating is used for mounting and
routing of all brake, door and electrical system
components. Components can be accessed
through the manhole covers mounted on the
upper deck.
MHT175-CAT777(G)-1
1 Aug 2012
MHT Door System ………….………….. 2-6
MHT Lube System ……………………… 2-7
MHT Lighting System …………….......… 2-7
Lower Hopper Assembly
The assembly is constructed of square steel
tubes, bolsters and plates. It provides for
mounting of door assemblies, hydraulic
actuators and lubrication blocks. The bolster
passage ways provide for the routing and
protection of hydraulic brake and door hosing
as well as electrical cabling.
Side Wall Assembly
The walls are constructed of steel tubes and
plates. They provide for mounting of
clearance lights, side boards and load markers.
2-1
MHT175-CAT777(G)-1
Wrap-Around Style
Push-Block Style
1 Aug 2012
System Description
Trailing Axle Frame Assembly
The trailing bogie is constructed of square
steel tubes and plates. The assembly provides
mounting for the rear axle assembly associated
brake system accumulators filters, manifolds,
and light. The rear of the bogie also contains a
push type bumper assembly.
The bumper may be configured as a pushblock or wrap-around style. The design
provides a pushing point to assist the MHT up
a grade in low traction conditions (wet, muddy
or icy haul road). The bumper assembly is
designed to be pushed straight on by the
pushing (boosting) machine.
SECTION 2
Proper straight on contact between MHT and
pushing (boosting) machine is shown below:
Routine hard bumper contacts by the pushing
(boosting) machine will cause structural
fatigue and result in reduced trailer service
life.
Angled blade contact of the push-block style
bumper will reduce bull dozer blade to MHT
wheel clearance. Extreme blade angles will
cause blade/bit to wheel contact and damage
MHT tires. MHT and pushing (boosting)
machine operators must communicate to
maintain correct contact and maximum wheel
to blade/bit clearance.
2-2
SECTION 2
Gooseneck
Stop
Turn Limit
Indicator
System Description
MHT AXLE & WHEEL GROUP
The MHT trailer axle and wheel group is the
same as the tractor drive axle assembly minus
drive gear. It is attached to the MHT trailing
axle frame by means of the same A-frame,
hard pan rod and struts. For more information
see the CAT operators/service manual and
brake system information contained in this
manual.
HITCH DECK AND FENDER
The hitch deck and fender is modular in design
and is comprised of three sub assemblies. The
assemblies are the hitch and saddles, deck and
fenders.
Hitch and Saddles
Constructed of steel plates and machined brass
bushings. The assembly is mounted to the
tractor chassis and pinned to the chassis pivot
bores. The machined brass bushings capture
MHT175-CAT777(G)-1
1 Aug 2012
the MHT hitch ball and transfer loads to the
tractor. Mounting is also provided for deck
and fender assemblies.
Deck and Fenders
Constructed of square steel tubes, plates,
channels and grates that mounts to the hitch
and saddle assembly. The assembly contains
fenders, mud flaps, maintenance access doors,
walkway and a work platform.
Turn Limit Indicator
Mechanical
Constructed of steel plate and mounted to the
tractor chassis rails and upper deck horse
collar. The turn limit indicator is designed to
contact the gooseneck stops and provide
visible indication of the maximum trailer
rotation left or right.
2-3
MHT175-CAT777(G)-1
Retainer Mounted Roller
In-Cab Mounted Warning
Box
1 Aug 2012
System Description
Electronic
The system consists of a roller switch mounted
on the hitch retaining plate and a warning box
located in the cab. The roller switch is
activated by flags mounted on the underside of
the ball skirt disc. When the trailer rotates
about 85° either side of center trail, the flag
will activate the switch in turn providing
power to activate the amber warning light and
audio horn on the warning box. The system
receives 24 VDC switched power from the
tractor.
MHT BRAKE SYSTEM
The MHT rear axle braking is integrated with
the existing CAT 777G tractor service,
secondary and parking brakes systems. MEGA
has added an additional scavenge pump one
additional accumulator (trailer mounted) a
modified brake valve and several restrictors
within the brake system to acquire a fully
functional cooling and activation system.
SECTION 2
The trailer brake activation is accomplished
with existing in-cab service brake pedal,
secondary brake control pedals as well as the
gear shift lever for parking brake.
Deceleration of the vehicle from running/
operating speed is typically accomplished by
using the retarder. Always consider road
conditions (wet, icy or slick) when
determining a means to decelerate or stop.
MHT Service Brakes
The tractor and MHT service brakes are
activated by pressing on the brake control
pedal. Pilot (signal) pressure from the tractor
proportions brake valves allowing accumulator
activation pressure to be routed to the slack
adjusters and apply the brakes.
Accumulators
The MHT is equipped with one additional
accumulators mounted on the trailing axle
frame that ensure brake activation pressure is
available in close proximity to the rear axle
brakes
2-4
SECTION 2
Hoist/Brake
Cooling Pump
Added
Scavenge Pump
Brake Pump
Tractor Brake Valve
Slack Adjusters
System Description
Brake Valve & Slack Adjuster Groups
The MHT is configured with two different
brake valve and slack adjuster groups. One is
mounted in the trailer rear axle and the other is
on the tractor chassis on the rear frame.
The trailer brake valve will route activation
pressure to the trailer slack adjuster to apply
trailer brakes. The activation should occur first
in the sequencing of the three axles (trailer,
tractor drive and tractor steering). This built in
delay ensures the trailer stays in trail during
initial brake applications.
The tractor drive axle brake valve will route
activation pressure to the chassis drive axle
slack adjusters to apply drive axle brakes. This
activation will be slowed down by restrictors
in the drive axle brake valve circuit. This
delay will allow drive axle activation to occur
second in the braking sequence.
Finally, the steering tire slack adjuster will
receive activation pressure at a further reduced
rate because of smaller restrictors feeding the
steering wheel slack adjuster. This delay will
ensure steering wheel activation occurs last in
the braking sequence.
Secondary Brake System
The tractor and MHT secondary braking are
activated by pressing on the secondary brake
control pedal. This action opens the brake
retract circuit allowing the spring activated
MHT175-CAT777(G)-1
1 Aug 2012
Parking Brake System
The tractor and MHT parking brake are
activated by moving the gear selector lever to
the park position P. This action opens the
brake retract circuit allowing the spring
activated parking brake to be applied.
Brake Cooling System
The MHT axles receive brake cooling oil from
the tractor torque converter through the oil
cooler circuit. Oil is returned to the tractor
cooling circuit through the added scavenge
pump.
Scavenge Pump
An additional scavenge pump was added to
assist in pulling MHT brake cooling oil back
into the tractor cooling circuit. This scavenge
pump is mounted between the tractor brake
cooling pump and the brake pump. Several
restrictors were added on the steering tire
cooling circuit to allow proper oil return flow
from the trailer. Otherwise the tractor drive
axle cooling circuit is unchanged and operates
per the CAT service/operators manual.
2-5
Loading...