The Caterpillar Asia Pacific Quarry Days, held on 3 – 7 June 2013 in Japan, assembled delegates from across the Asia Pacific area to discuss Caterpillar products, technology and services. Broken into two sessions for low-regulated and high-regulated countries in the Asia-Pacific and Australasia region, the event took its guests from downtown Tokyo to the quarry and aggregate machinery manufacturer's Chichibu Demonstration Centre, the largest training centre for construction machinery in Asia. Global Cement attended at the kind invitation of Caterpillar.
Quarry Days covered a wide range of Caterpillar's products and services so this article will concentrate on those with a direct application for the cement industry. Both sessions of the event comprised a day of classroom sessions in Tokyo, followed by a day 'in the iron' (to use Caterpillar speak) at the Chichibu
Demonstration Centre. Here guests could see and clamber over the latest models of hydraulic excavators, hammers, large wheel-loaders, off-highway trucks and more. Participants were even able to take their prospective purchases for test-drives around the facility.
Caterpillar Japan
Caterpillar Japan was founded in 1963. Headquartered in Tokyo, the company has two manufacturing plants: the Sagami Plant in Tana near to Tokyo and the Akashi Plant / Hydraulic Excavator Development Centre in Shimizu near to Osaka in southern Japan. It also supports the Chichibu Demonstration Centre located in Chichibu.
Originally created as a joint venture between Caterpillar International and Mitsubishi Heavy Industries, Caterpillar became the sole owner of the US$236m business in 2012. There are currently over 5000 employees in the Caterpillar Japan Group.
The Akashi Plant focuses on building hydraulic excavators with a wide variety of components on one main assembly line. It also houses the company's hydraulic excavator design centre. Another plant, Sagami, builds a wider range of Caterpillar machines including smaller hydraulic excavators, wheel loaders, track-type tractors and components on two main assembly lines. The majority of machines shipped from both plants are supplied to overseas markets around the world.
Chichibu Demonstration Centre
Caterpillar's state-of-the-art Japanese demonstration centre resembles a horse racing pavilion overlooking a golf course with a giant aggregates hazard. It is one of four centres the machine manufacturer has across the world. The other centres are located in Malaga (Spain), Tinaja Hills (Arizona, US) and Edwards (Illinois, US). Chichibu is the largest facility of its kind in Asia. It is used for both demonstrations and training.
The centre covers 295,000m3 on the outskirts of Chichibu, a medium-sized Japanese town in the mountains, about 100km from Tokyo. Established in 1979, the centre has an enclosed pavilion overlooking a 31,000m3 demonstration area, holding three haul roads of gradients of 9 - 15% and a weighbridge. The site also holds a training area for prospective buyers and current operators looking to improve their skills.
On arrival at Chichibu delegates from Quarry Days were treated to the spectacle of a radio-controlled 320 D Medium Hydraulic Excavator delicately opening a 'present' carried by a loader. As the tinsel-covered excavator held up the contents of the box, fireworks were released to the merriment of onlookers.
Large wheel loaders
Don Weinhold, Senior Market Professional – Aggregates Industry (Global), a veteran with 32 years with Caterpillar, presented the large wheel loaders (LWL) in the classroom and at Chichibu.
LWLs can be used for both loading and hauling stages of material extraction in a quarry. They can perform multi-face loading tasks because they are highly mobile. Their mobility and large bucket capacities enable them to also perform load-and-carry operations. Those same large buckets make it more difficult for wheel loaders to fill the bucket when digging difficult materials.
On the hauling stage Caterpillar recommends using a LWL for distances less than 100m. Typically though a LWL is used with an off-highway or an articulated truck and each model of LWL is designed to work best with specific models of haulage trucks ('pass match').
In Tokyo, Weinhold discussed key features of a new model, the 986 H, and the latest H version of the 988 model. The 986 H is a 42t wheel loader targeted at emerging markets, a lower-sized entry in Caterpillar's LWL range. At specification it can load the 770 G off-highway truck (38.6t capacity) in four passes or when equipped with a high lift front linkage it can load the 772 G (47.7t capacity) in five passes.
Key features mentioned included how bucket design can affect fuel efficiency. For example, using the correct bucket can improve fuel efficiency by 5 - 7% and/or improve the fill factor of a bucket by 10 - 15%. However using a larger bucket for an LWL than is recommended introduces a trade-off between increased bucket fill versus (eventual) reduced machine life. Weinhold suggested that each case should be looked at individually.
Linkage was an issue raised by customers for the 988 model where clearance in underground mines was of concern. For the 988 H this has been improved with a box boom linkage design. This feature uses high strength castings in pin joint areas that resist twisting and minimise stress.
On the 988 H Weinhold pointed out the benefits of the Impeller Clutch Torque Converter (ICTC) combined with the Rimpull Control System. The ICTC can reduce rimpull – the friction force between wheels and contact surfaces – to reduce tire slippage and wear.
Many factors affect fuel efficiency such as the engine, load sensing hydraulics, lock-up clutch torque converters, transmission shifting and more. However the other factor is the operator. Weinhold gave the example of operators who don't use Variable Shift Control, increasing fuel usage by 15% in the process. Overall though engine RPM determines fuel burn, so using tools like the Variable Shift Control - which automatically sets the gear to the designated application - keeps the RPMs down as low as possible for the desired task.
At the Chichibu Demonstration Centre delegates were able to view the 988 H and 992 K models.
| Model | Power | Operating Weight | Bucket Capacity |
| 986 H | 305kW | 42t | 5.3 - 6.1m3 |
| 988 H | 373kW | 50t | 6.4 - 7.7m3 |
| 992 K | 607kW | 100t | 10.7 - 12.3m3 |
Above - Table 1: Operating specification for selected models of large wheel loaders.
Off-highway trucks
Roy Pang, Caterpillar Singapore-based haulage truck specialist, compared quarry (QT) and articulated trucks (AT). The key difference between the truck types is the joint that the articulated truck has, allowing better stability on higher gradients (up to 20%) and on low-grade quarry roads. However QTs can carry far greater loads and are recommended for longer haulage routes.
Key features that Pang pointed out for the QTs were the fuel conservation methods, including Auto Neutral Idle, Engine Idle Shutdown, Speed Limiting and Transmission Controls. Engine Idle Shutdown, for example, shuts down the truck to conserve fuel after a preset period of idle behaviour. Specifically the latest series of QTs come with economy modes that can be varied across a fleet of machines by either manually reducing power or adaptively based on a pre-set baseline.
The other feature that Pang mentioned was the Vital Information Management System (VIMS). This data collection tool collects analytical data on machine performance that can be used to detect faults and notify the operator whether remedial action should be taken or if maintenance is required. Specifically for the larger quarry trucks VIMS records production and performance data of the truck cycle such as load time, travel loaded, dump time and travel empty and delay times. Crucially this information can then be used to report on machine and operator behaviour to improve overall performance.
At Chichibu delegates had the chance to view the 725 AT and the 773 G QT. Focusing on the QTs, Pang pointed out the 773 G's focus on safety, starting with the model's dedication towards supporting an operator's three points of contact when climbing into or out of the machine.
The 773 G includes a Truck Production Management System that can calculate the weight of a load after the first loading pass and determine how many passes it will take to fill the truck body. Then on the final pass indicator lights alert the loader that the hauler is about to leave.
Pang followed this by reiterating Caterpillar's 10/10/20 payload policy. In short this recommends that the mean of the payload distribution shall not exceed the target payload, no more than 10% of payloads may exceed 1.1 times the truck target payload and no single payload shall ever exceed 1.2 times the target payload.
Other features that the G series introduced are a traction control system designed to be more responsive in wet conditions. QTs also offer a variety of body options starting with dual-slope, for grades of 12% or higher, and flat-floor for lower grades. The linings can be modified to maximise body life and operator comfort. The 773 G comes with a rubber lining that is optimised for hard rock usage. For limestone haulage Caterpillar offers a body specifically for low to medium density/abrasive material made of 400 BNH steel with a 25mm floor.
| Model | Power | Nominal Capacity | Top Speed |
| 773 G | 546kW | 54.4t | 67.5km/hw |
Above - Table 2: Operating specification for a selected off-highway truck.
Fuel efficiency demonstration
One of the more impressive demonstrations at Chichibu was a comparison of poor and best practice when loading a haulage truck and a visible demonstration of the difference in fuel burn this made. Watching the show from the centre pavilion afforded onlookers real time information such as the fuel consumption in the haul truck and readouts from the weigh-station.
Delegates watched as a 773 G QT carried out two hauling cycles. The first cycle showing bad practice including poor loader/truck alignment, inappropriate haul distance and bumping into the QT. Under these circumstances filling the QT took six passes, gaining a payload of 56.8t and it took 593s. By contrast the best practice run took four passes to fill the QT, with a payload of 54.4t and a cycle time of 399s.
It can be seen in Table 3 that, despite delivering a smaller payload, the best practice run was quicker and used less fuel in the process. This in turn allows for a greater production per hour with lower fuel consumption per cycle. In the demonstration the best practice run produced a fuel efficiency of 15.17t/l, a 23% improvement on the poor practice run.
It should be noted that although the demonstration was carried out at a Caterpillar centre using Caterpillar machines, best practice from this example for maximal fuel efficiency could be applied to any comparable machine made by Caterpillar's competitors.
| Operator | Good | Bad | ||
| Cycle time |
SEC |
398.9 | 592.89 | |
| Cycles per hour |
Cycles/hr |
9.02 | 6.07 | |
| Production | Truck loaded weight | t | 105.6 | 108 |
| Payload | t | 54.4 | 46.8 | |
| Production per hour | T/hr | 490.95 | 344.89 | |
| Fuel Efficiency | One-cycle | L | 3.587 | 4.887 |
| Fuel consumption per hour | L/hr | 32.37 | 29.67 | |
| Fuel Efficiency |
t/L |
15.17 | 11.62 | |
| +23% | ||||
Above - Table 3: Table showing the effect operator behaviour can have on fuel efficiency as a 773 G series off-highway truck completes its haulage cycle.
Ryougami-Kougyou sandstone quarry visit
Press delegates at Quarry Days were also invited on a tour of the Ryougami-Kougyou company quarry in Ogano, near Chichibu.
This sandstone quarry currently has an area of 106 hectares and is split into two sites. The company was originally established in 1966 and it employs 36 workers. In 2012 its output was 800,000t, although the site has a total production capacity of 1Mt/yr. The two sites are expected to remain viable for up to 30 and 50 years respectively. Common uses for the sandstone from this quarry are in concrete and ballast for road or railway lines. Future quarrying at the location should yield aggregates for up to 350 years.
With a blast frequency once every two days, two hydraulic excavator models 385 C load QTs for haulage to the primary crusher. The haul distance at the Ryougami-Kougyou quarry was up to a maximum 2km, with only one road leading from the blasting face to processing. Good practice including haul trucks returning quickly from dumping to queuing for the excavators was observed, leaving little idle time for the excavators.
