Shovel lubricants are specialized lubricants used to protect the open gears and other heavily loaded components of electric mining shovels and draglines. These machines operate under high loads, shock loading, dust, moisture and changing temperatures, making lubricant selection an important part of equipment reliability and maintenance.
The right shovel lubrication strategy depends on more than lubricant viscosity. Equipment design, the lubrication point, ambient and operating temperatures, application method, OEM requirements and the required lubricant film all need to be considered.
For open-gear applications, Petron Corporation’s Petrotac EP Premium range provides different formulations for shovel and dragline equipment across a range of ambient temperatures. Draglines with walking mechanisms have additional requirements, with specialized walking cam lubricants available for rails and cams.
What are shovel and dragline lubricants?
Mining shovels and draglines contain multiple components that require lubrication to reduce wear and protect surfaces under demanding operating conditions.
One of the most critical applications is open-gear lubrication. Unlike enclosed gears that operate inside a sealed housing, open gears are exposed to the surrounding environment. Their lubricant must remain on the gear teeth while providing protection against heavy loads, shock loading and surface wear.
A dragline may also require lubrication for pins, bushings, rails, rollers, racks, pinions and walking mechanisms. Because these components perform different functions, the lubricant used for one application should not automatically be assumed to be suitable for another.
In simple terms, lubrication for draglines and electric shovels should be application-specific. The correct lubricant needs to match the component, operating conditions and lubrication system.
Why do open gears need specialized lubricants?
Open gears on large mining shovels and draglines transmit substantial loads through their gear teeth. They also operate in environments where dust, water and other contaminants can affect lubricant performance.
A suitable open-gear lubricant needs to maintain a protective film between mating gear surfaces under operating conditions. Adhesion is also important because the lubricant needs to remain on the gear teeth rather than being displaced during operation.
Film thickness is another important consideration. Petron’s EHD Film Thickness Analysis evaluates lubricant film performance using factors such as gear geometry, speed, power, tooth temperature and lubricant characteristics.
The objective is to establish whether the lubricant can provide an adequate film under the actual operating conditions of the gear set.
This is particularly relevant when selecting a dragline lubricant or lubricant for a large electric shovel, where equipment operating conditions can vary significantly from one site to another.
Where is lubrication required on shovels and draglines?
The exact lubrication points and service intervals depend on the machine and OEM requirements. However, common applications include:
- Open gears: Large gear sets transmitting high loads require specialized open-gear lubrication.
- Pins and bushings: These components experience high loads and repeated movement.
- Rails and rollers: Dragline walking mechanisms can require lubrication of rails and associated moving surfaces.
- Walking cams: Walking mechanisms require specialized lubrication to protect the cam and rail contact surfaces.
- Racks and pinions: These components require lubrication appropriate to their load and operating conditions.
Petron’s mining lubrication range includes products for open gears, pins, rails, rollers, racks and pinions, as well as dedicated walking-cam applications.
The important principle is that shovel lubrication should be designed around the individual application rather than using one lubricant indiscriminately across the entire machine.
How to choose the right Petrotac EP Premium lubricant
Temperature is one of the most important factors when selecting an open-gear lubricant for a shovel or dragline.
Petron’s Petrotac EP Premium range includes four formulations with published ambient-temperature ranges suited to different operating conditions.
| Petrotac EP Premium Lubricant | Published Ambient-Temperature Range |
|---|---|
| 30B | -7°C (20°F) and above |
| 20B | -26°C (-15°F) to 25°C (77°F) |
| 10B | -7°C (20°F) and below |
| Arctic | -40°C (-40°F) to 0°C (32°F) |
These published ranges provide a starting point for selecting a dragline lubricant or shovel open-gear lubricant. However, temperature should not be the only selection criterion. OEM requirements, gear design, operating temperature, load, lubrication system and application method should also be evaluated.
Petrotac EP Premium 30B
Petrotac EP Premium 30B is specified for ambient temperatures of -7°C (20°F) and above.
It is a high-viscosity synthetic open-gear lubricant intended for demanding shovel and dragline applications. It can be considered where operating conditions fall within its published temperature range and where it meets the equipment’s lubrication requirements.
Petrotac EP Premium 20B
Petrotac EP Premium 20B has a published ambient-temperature range of -26°C (-15°F) to 25°C (77°F).
Its broad range makes it an option for operations that experience substantial changes in ambient temperature. As with any lubricant selection, the actual equipment requirements and lubrication system should be evaluated before making a product choice.
Petrotac EP Premium 10B
Petrotac EP Premium 10B is specified for ambient temperatures of -7°C (20°F) and below.
It provides an option for open-gear applications operating in colder environments where the lubricant needs to perform within lower ambient-temperature conditions.
Petrotac EP Premium Arctic
For more extreme cold, Petrotac EP Premium Arctic has a published ambient-temperature range of -40°C (-40°F) to 0°C (32°F).
This makes it particularly relevant when evaluating shovel lubricants and dragline lubricants for operations exposed to severe cold.
How do shovel lubricants differ by operating temperature?
Shovel lubricants differ by operating temperature because temperature affects lubricant flow, application and film performance. As temperatures decrease, lubricants generally become more resistant to flow. This can affect lubricant delivery through an automatic lubrication system and the ability of the lubricant to reach the intended surface.
At higher operating temperatures, the lubricant needs to maintain appropriate viscosity and protective film characteristics under the actual gear operating conditions.
For this reason, Petron’s Petrotac EP Premium range provides different formulations across different ambient-temperature conditions.
A practical starting point is:
- -7°C and above: Petrotac EP Premium 30B
- -26°C to 25°C: Petrotac EP Premium 20B
- -7°C and below: Petrotac EP Premium 10B
- -40°C to 0°C: Petrotac EP Premium Arctic
These ranges overlap, so this should not be treated as a standalone product-selection formula. The appropriate product should also be evaluated against OEM specifications, equipment operating conditions and lubrication-system requirements.
For critical open gears, an EHD Film Thickness Analysis can provide a more application-specific assessment by evaluating the lubricant against the actual characteristics of the gear set.
What is walking cam lubrication?
Walking mechanisms create a different lubrication requirement from the main open gearing on a dragline.
Walking cam lubricants are designed for the contact surfaces involved in walking mechanisms. Petron’s Petro Cam WCL is specifically designed for draglines with walking mechanisms requiring lubrication of rails and cams.
This is an important distinction when choosing a lubricant for drag lines. A product selected for open-gear lubrication should not automatically be substituted for a lubricant specifically intended for walking cams.
Petron’s walking-cam trial
Petron has published results from a trial of its walking-cam lubricant on a Monighan walking-cam mechanism.
During the cited trial, the industry average was lubrication at every step. Petron reported that its walking-cam lubricant ran for four to five steps without noticeable film thinning or loss of adhesiveness, while competing products tested lasted approximately two to three steps before noticeable issues occurred.
The result demonstrates why the lubrication requirement of a walking mechanism should be considered separately from the open gears.
It also provides a useful performance consideration when evaluating walking cam lube: how long can the lubricant maintain a protective film and adhesion under the actual walking mechanism’s operating conditions?
The reported trial result should be understood as trial-specific performance information rather than a universal lubrication interval for every dragline.
What is the best lubricant for dragline gearing?
The best lubricant for dragline gearing depends on the gear set, operating temperature, load, application system, OEM requirements and required lubricant film performance.
There is therefore no single lubricant that can automatically be considered the best for every dragline.
For open gears, Petron’s Petrotac EP Premium range provides different formulations for different ambient-temperature conditions. The selection can then be refined by considering the equipment’s specifications, lubrication system and operating conditions.
For particularly demanding applications, EHD Film Thickness Analysis can help determine whether the selected lubricant provides an appropriate film under the actual gear-set conditions.
The best dragline lubricant is ultimately the one that meets the equipment requirements and provides reliable protection under the conditions in which the machine operates.
Common shovel and dragline lubrication mistakes
Even a high-performance lubricant can underperform if the lubrication program or application is incorrect.
1. Selecting lubricant based only on viscosity
Viscosity is important, but it is only one part of lubricant selection. Temperature, load, gear design, application method and film performance also need to be considered.
2. Ignoring temperature changes
A mine may experience significant seasonal or daily temperature variations. Selecting a lubricant without considering the full operating-temperature range can create pumping, application or film-performance challenges.
3. Using the same lubricant for every application
Open gears, pins, bushings and walking cams have different operating requirements. Application-specific lubricant selection is therefore important.
4. Applying insufficient lubricant
If lubricant does not adequately cover the required surfaces, the protective film may not be maintained. Application rate and coverage should therefore be monitored.
5. Applying excessive lubricant
More lubricant does not necessarily mean better lubrication. Excessive application can increase consumption and create unnecessary buildup.
6. Overlooking the lubrication system
A lubricant needs to reach the component it is intended to protect. Pumps, spray systems, delivery rates and application timing should be checked as part of the maintenance program.
7. Failing to monitor equipment condition
Lubrication should work alongside condition monitoring. Gear-tooth condition, wear, operating temperature, lubricant film and consumption trends can provide useful indicators of equipment and lubrication performance.
How often should draglines be lubricated?
There is no single lubrication interval that applies to every dragline. The required frequency depends on the component, equipment design, lubricant, operating environment, application system and OEM recommendations.
For example, open-gear lubrication requirements can differ from lubrication requirements for walking cams, pins or bushings.
Petron’s published walking-cam trial reported operation for four to five steps without noticeable film thinning or loss of adhesiveness, compared with an industry-average lubrication frequency of every step during the cited trial.
This does not mean every dragline should automatically be lubricated every four or five steps. Instead, it illustrates how lubricant performance can affect application frequency and lubricant consumption under specific operating conditions.
The appropriate maintenance interval should be established using OEM recommendations, operating conditions, equipment monitoring and actual lubricant performance.
Shovel and dragline lubrication maintenance checklist
A structured maintenance program can help identify lubrication problems before they develop into equipment failures.
Before selecting a lubricant
- Check the OEM lubrication requirements.
- Identify the exact component being lubricated.
- Determine the ambient and operating temperature range.
- Confirm compatibility with the lubrication system.
- Check the required lubricant type and viscosity.
- Consider load, speed and operating conditions.
During routine maintenance
- Check automatic lubrication-system operation.
- Verify lubricant delivery rates.
- Inspect spray equipment and application points.
- Check gear-tooth coverage.
- Look for lubricant wash-off or contamination.
- Inspect gears for abnormal wear or surface damage.
- Check pins and bushings.
- Inspect rails, rollers and walking cams.
- Monitor lubricant consumption.
- Record changes in operating temperature or equipment behaviour.
During lubricant evaluation
- Compare actual operating conditions with the product’s published range.
- Monitor film performance and equipment condition.
- Investigate abnormal lubricant consumption.
- Consider EHD Film Thickness Analysis for critical open-gear applications.
- Review lubricant performance against the site’s maintenance objectives.
Frequently Asked Questions
What lubricant is used for mining shovels?
Mining shovels typically use specialized open-gear lubricants for heavily loaded open gears, along with application-specific lubricants for other components. Petron’s Petrotac EP Premium range is designed for open-gear applications on shovels and draglines, with formulations covering different ambient-temperature conditions.
How often should draglines be lubricated?
Dragline lubrication frequency depends on the component, equipment design, lubricant, operating conditions and OEM requirements. There is no universal interval for every dragline. Petron’s published walking-cam trial reported four to five steps without noticeable film thinning or loss of adhesiveness, compared with lubrication at every step as the industry average cited in that trial.
What is the best lubricant for dragline gearing?
The best lubricant for dragline gearing is the product that meets the gear manufacturer’s requirements and provides suitable film performance under the equipment’s actual operating conditions. Temperature, load, gear geometry, application system and lubricant characteristics should all be considered. Petron’s Petrotac EP Premium range provides multiple formulations for different ambient-temperature conditions.
How do shovel lubricants differ by operating temperature?
Shovel lubricants are formulated for different temperature conditions because temperature affects lubricant flow, application and film behaviour. Petron lists Petrotac EP Premium 30B for -7°C and above, 20B for -26°C to 25°C, 10B for -7°C and below, and Arctic for -40°C to 0°C. These ranges overlap, so OEM requirements and actual operating conditions should also be considered.
What are walking cam lubricants used for?
Walking cam lubricants are used to lubricate the rails and cams of draglines equipped with walking mechanisms. Petron’s Petro Cam WCL is specifically designed for this application.
Can the same lubricant be used for open gears and walking cams?
Not necessarily. Open gears and walking mechanisms have different lubrication requirements. A lubricant should be selected according to the component, operating conditions, OEM specifications and application system. Petron offers separate solutions for open-gear and walking-cam applications.
Choosing the right lubricant for your shovel or dragline
Effective lubrication starts with understanding the equipment and its operating conditions.
For shovel lubricants and dragline open-gear applications, begin by identifying the component, reviewing OEM requirements and establishing the full ambient and operating-temperature range. Then evaluate the lubrication system, lubricant film requirements and actual equipment conditions.
Petron’s Petrotac EP Premium 30B, 20B, 10B and Arctic formulations provide options across different ambient-temperature conditions. For draglines with walking mechanisms, Petro Cam WCL provides a dedicated walking-cam lubrication solution for rails and cams.
For critical open gears where a more detailed evaluation is required, EHD Film Thickness Analysis can help assess lubricant film performance against the characteristics of the actual gear set.
The objective is not simply to find a lubricant that works. It is to establish a lubrication program that provides the required protection, supports equipment reliability and manages lubricant consumption under the conditions in which the shovel or dragline operates.
Compare your shovel or dragline lubrication requirements and explore the appropriate lubricant range.