Redesigned for the digital age

Including predecessor models from the yesteryears of the Toro brand, Sandvik LH621 has proven productive in demanding mucking applications for several decades. In 2015 it became clear to the experts at Sandvik’s loader and truck plant in Turku, Finland, that their flagship Sandvik LH621 needed a facelift and new intelligent solutions to tackle the challenges of increasingly connected and digitalized mining ecosystems.

The result, Sandvik LH621i, provides a matching pair with the previously introduced Sandvik TH663i truck. The two forge yet another link in the Sandvik i-series of intelligent underground mining equipment that includes Sandvik LH517i loader and Sandvik TH545i and Sandvik TH551i trucks.

“We started out with our customers,” says Olli Karlsson, product line manager, large loaders at Sandvik Mining and Rock Technology. “We asked them first what would best serve their needs: Would they like to have a totally new machine made from scratch, or should we rather start with the existing loader, keep what is good and update where needed?”

Another significant change is the new spacious and ergonomic cabin that largely builds on Sandvik TH663i truck’s successful design philosophy. Redesigned leg space and pedal positions significantly improve operator comfort. A new window was added to improve over-shoulder visibility and powerful LED lights to further improve visibility from the cabin. A seven-inch touch-screen colour display merges all the main information and alarms in one place, which makes it easier for operators to keep their eyes where they should be: on the road. The ROPS/FOPS-certified cabin is a modern, ergonomic workplace that enables comfortable operation and indirectly also improves productivity.

High productivity is one of Sandvik LH621i’s fundamental features. The main ingredients for more tonnage per shift include several key areas of the boom and bucket mechanics and hydraulics. The optimized boom geometry increases hydraulic power and enables faster bucket filling and effective handling of oversized boulders. The new hydraulic circuit for the boom and bucket supplies a higher flow and more efficient bucket-shaking functionality for faster dumping times. An upgraded drivetrain provides more power and higher ramp speeds. In a nutshell, Sandvik LH621i is designed to quickly clear tunnel headings, ensuring rapid development.

Any profitable operation requires high productivity and minimized tonnage costs. The load-sensing hydraulics help to reduce heat generation and fuel consumption by providing on-demand pressure and increased efficiency. Cost-effective design is another cost-cutting strategy, and with Sandvik LH621i this means durability-optimized structural solutions, such as a heavy-duty rear frame and mask to minimize impact damage and shock-resistant welded steel box structures in the frame and boom. The rugged structural solutions reduce stresses, extend frame lifetime and provide a superior strength-to-weight ratio. The service life of key components has been increased by new cooling and brake systems.

Another factor in Sandvik LH621i that has reverberations affecting safety, productivity and sustainability is maintenance friendliness. To start with, the seven-inch colour display provides the operator with a clear overview of all key diagnostics and alarm log files, which minimizes the need to move around the loader for troubleshooting. A large number of changes and adjustments were carried out to centralize service access and provide better maintainability and easy access to the components, most of which are reachable from the ground level.

Safety rails are available to improve safety when working on top of the equipment. Underground mine environments can beinherently hazardous. Sandvik LH621i includes numerous features that help ensure operators and maintenance personnel return home from work safely every day: an ergonomic FOPS/ROPS cabin with optimized visibility, high-power LED lights, ground-level access to maintenance points, anti-slip steps and many more.

The standard engine in Sandvik LH621i is a fuel-efficient Tier 2/Stage II powerplant. When ultra-low-sulphur diesel fuel is available at the mine site, the low-emission Tier 4F/Stage IV engine can be considered as an option. Sandvik has a staunch commitment to implement the latest engine technologies when available and thus comply with regulations.

The sustainability thinking behind Sandvik LH621i focuses on tangible factors that have significant bearing on the operators’ and maintenance crews’ everyday work and the measurable sustainability performance of the mine. “Our approach is very practical,” Karlsson says. “We make a good machine, look at it from every angle and optimize all the relevant characteristics to achieve tangible real-life benefits.”