Is Poor Maintenance Shortening Your TBM’s Life Span?

By Emily Newton

Few, if any, pieces of equipment are more important in this industry than the tunnel boring machine (TBM). Given that cruciality, digging teams must do all they can to extend their TBMs’ life spans. Still, many fall short in doing so.

While usage errors play a role in TBM damage, improper maintenance is typically the driver of short machine lives. Recognizing where businesses often go wrong is the first step to reversing this trend.

Why Does Tunneling Equipment Need Better Maintenance?

Proactive care is about more than preventing breakdowns and the delays they incur. Studies show advanced repair strategies can extend equipment availability by 20%, letting teams get more value from their machinery. Such returns are particularly crucial for anything as expensive as a tunnel boring machine.

The importance of proper upkeep may seem obvious, but subpar repair practices are a common problem. Bertha, the largest TBM in the world, was offline for two years, costing millions of dollars due to mechanical issues. Had teams recognized issues in its bearings and seals ahead of time and addressed them, they might’ve avoided such substantial losses.

Poor maintenance can affect the life span of any TBM if it’s enough to bring Bertha down for years. While some companies may hesitate to spend more on proactive repairs, the cost is far lower than the expense of fixing a larger breakdown or, worse, replacing the TBM altogether.

Tunnel Boring Machine Maintenance Tips

One of the reasons why tunneling equipment care falls short so often is because teams don’t understand the alternative. Consequently, learning a few best practices can go a long way.

Develop a Routine

The first and most critical step is to move past a run-to-failure method. Reactive repairs are the unofficial standard in many sectors because they’re the easiest, but they’re also costlier and the most harmful in terms of equipment longevity.

Instead, tunneling teams should refer to their TBM’s manufacturer for guidelines on when to address various components. Final drive motors’ gear oil requires inspection every 100 operating hours or each month, whichever comes first. Hydraulic fluid and cutting edges benefit from daily checks.

After reviewing these considerations, team leaders should develop a formal schedule and assign responsibilities to specific employees. That way, no one can assume someone else will perform needed inspections, and repair routines become a matter of policy. Having workers sign off on all care steps is likewise important, as it shows who’s responsible for which tasks, motivating additional care.

Consider Predictive Maintenance

Operations with enough room in the budget can go further and implement predictive maintenance (PdM). This practice involves using Internet of Things (IoT) sensors to monitor TBM conditions in real time and alert workers of impending repair concerns.

PdM is beneficial because it detects issues far earlier than manual checks and minimizes planned downtime. Roughly 30% of preventive care activities add no value because breakdowns don’t occur on regular timelines. Using real-time data and predictions instead lets teams ensure all repairs address needed issues.

As helpful as PdM can be, though, it’s not the right choice for all tunneling equipment. IoT systems are expensive, and the predictive models necessary for this strategy can be difficult to deploy effectively. Consequently, it’s a good fit for high-budget projects and tech-savvy businesses but not for smaller dig projects or those facing tighter deadlines.

Choose Replacement Parts Carefully

When it comes time to replace TBM components, organizations should take a second to review their options. Right-sizing the part for the job and machine at hand will reduce future maintenance concerns. By the same token, a subpar replacement may lead to further issues.

Generally, larger-diameter cutting surfaces are preferable, as they can withstand more damage. However, teams should also consider these discs’ seal material and sizes to ensure they can put up with the current project’s ground conditions. The type of drive also deserves consideration, as higher-power, high-rotation options are ideal for hard, rocky environments, while softer ground necessitates a slower rotation.

Businesses should also vet their suppliers, looking at industry certifications and customer reviews to ensure their reliability. Supply chain counterfeiting is surprisingly common in some industries, and counterfeit parts will dramatically decrease a TBM’s life span.

Tailor Repair Strategies to Individual Jobs

Similarly, drill teams must recognize that there’s no one-size-fits-all solution to the optimal maintenance schedule. Repair timelines and strategies must adapt to different projects, as each operating environment presents unique hazards affecting TBM wear and tear.

Natural conditions impact tunneling accidents more than any other factor, so thorough geological surveys are necessary before each dig. Once firms know what kind of ground and potential infrastructure they’re dealing with, they can tailor their care strategy accordingly.

Tunnel boring machines will need more frequent inspections and repairs in rockier soil than they will in softer ground. Such conditions affect which maintenance steps are most important, too. While soft soil may make cutting head damage a less pressing matter, it raises muck-related concerns, so employees should pay greater attention to sump lubrication and muck buckets.

Train All Employees in Proper Maintenance

Human error is another significant part of tunneling equipment damage and repairs. An ill-trained team is likelier to run a TBM improperly or fail to perform maintenance duties effectively. Consequently, businesses must train all workers in TBM repair best practices.

This training starts with teaching employees to recognize signs of wear and tear. An inspection does little good if the person performing it misses crucial evidence. Automating these checks through IoT sensors is also a good solution to the same problem, but not every project has the budget for IoT systems.

Likewise, anyone working on a TBM should know a few basic repair practices, such as how to refill fluids, patch leaks or change out crucial components. Complex steps may need a specialized professional, but everyone involved needs at least a baseline knowledge of how to fix common issues.

Keep Tunneling Equipment Running for Longer

Tunnel boring machines need proactive maintenance to last as long as they can. When firms follow these practices, they can get more out of their equipment investments and complete projects on time. Without such care, things will become costlier and more time-consuming before long.

Every job has unique repair considerations. However, starting with these basics will prevent many avoidable accidents and downtime.

Emily Newton is a construction and industrial journalist. She enjoys exploring the impact technology has in the construction and utilities sectors. When Emily isn’t writing, she enjoys building Lego sets with her husband.