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Inside the Miner's Backpack


Over the past year, a dedicated LTT fan assessed the durability and functionality of the LTT Backpack in the demanding setting of an underground coal mine.This evaluation is not just about a stylish backpack; it addresses the critical needs of professionals like Jacob Frashure, who work in challenging conditions, emphasizing the importance of gear that delivers great performance day after day, and ensures that they can focus on safety and efficiency on the job.

Jacob, a maintenance worker in an underground coal mine, relied on the LTT Backpack for an entire year, subjecting it to challenging and sometimes harsh conditions in the mining industry.


The selection of the LTT Backpack was deliberate on the part of Jacob, driven by its established reputation for durability and functionality. Our evaluative framework was structured around critical components, encompassing fabric quality, pocket functionality, zipper durability, and overall resistance to wear and tear. The evaluation period extended over the course of a year, during which Jacob's backpack underwent a comprehensive assessment, ensuring a nuanced understanding of its enduring performance characteristics. This methodological approach was adopted to provide a thorough and informed analysis of the backpack's sustained resilience under prolonged usage.


Backpack Overview 

The LTT Backpack, designed to cater to the needs of professionals in various environments, boasts distinctive features. With 22 pockets and sleeves, it offers versatile utility for daily use. Notably, all straps and stitches have been reinforced significantly beyond the standard requirements, including a triple-rivet-reinforced top handle capable of withstanding a pull force of 778.6N. The primary material is a robust 900D Repreve Polyester, complemented by a water-resistant lining subjected to rigorous testing, achieving an AATCC water repellency rating of 80. Moreover, in alignment with sustainability goals, the backpack's material is entirely composed of recycled plastic water bottles, a hallmark of the Repreve brand. The incorporation of renowned YKK zippers, water-resistant across external pockets and featuring standard YKK zipper pulls on all zippered compartments, adds to the backpack's reliability.

Upon the initial evaluation of Jacob's backpack, it exhibited commendable resilience in the face of harsh conditions. While acquiring a subtle patina, the backpack demonstrated no major structural changes or damages. Covered in dust, dirt, and debris from the challenging work environment, the initially vibrant orange lining transitioned to a dull hue. Notably, the zipper pulls and teeth displayed signs of wear, and the laptop pocket zipper interlocking components of the zipper failed to properly engage or maintain closure, leading to the separation of the zipper tracks and potential opening of the backpack. These preliminary impressions underscore the backpack's durability and capacity to withstand demanding circumstances.


Fabric Evaluation 

The primary exterior Repreve fabric exhibited visible signs of wear, marked by a transition from true black to a grayish brown. Notably, this fabric showcased commendable resilience against surface abrasion, as evidenced by a small rip at the bottom of the bag. Jacob suggested that the scuff likely resulted from contact with metal surfaces, and it is noteworthy that exposure to high environmental temperatures from mechanical equipment in the mine, reaching 114 degrees Fahrenheit, did not yield visible wear or damage.

The interior Repreve and ripstop lining underwent a notable color change from vibrant orange to a subdued tone due to accumulated dirt and staining. Despite serving as a carrier for various tools, including hand tools, a multimeter, paint pens, jumpers, and lockout tags, the lining displayed no surface abrasion, showcasing the durability found in our pre-launch testing.

The mesh interior lining in the front pocket of the backpack - subjected to rigorous use - presented evident dirt accumulation and a distinct color shift from vibrant orange to a more muted shade. Despite these external effects, the mesh structure remained intact, exhibiting no frayed edges or holes, reaffirming its resilience in the context of extended use.

The Microsuede fabric in the laptop/tablet section of the backpack underwent a significant color change from vibrant orange to a dull hue, accompanied by some pilling on the fabric surface. However, the surface of the microsuede displayed resilience, with no notable abrasions or punctures. Collectively, these fabric evaluations provide valuable insights into the backpack's ability to withstand varied conditions, offering a nuanced understanding of its strengths and showcases what wear could be expected through harsh or “extreme” use cases - typically resulting in changes to surface appearance and color.

Pocket Assessment 

The backpack's design incorporates a total of 22 pockets and sleeves strategically placed for a diverse range of daily uses. With an internal carrying capacity of 25.5L and an external volume of 35L, the backpack features ample padding and reinforcement throughout its structure, including the spaces between pockets and beneath the laptop sleeve.

Each pocket serves a distinct purpose in enhancing the backpack's functionality. Jacob utilized the laptop/electronic pocket to accommodate a tool bag weighing over 8 pounds, alongside other tools, a backup pair of glasses, hand tools, papers, and field notebooks. The middle pocket, equipped with ripstop lining, was designated for carrying lunches and snacks. In the front pocket, Jacob stored smaller items such as leads for a multimeter, paint pens, and jumpers, while the mesh pocket housed essentials like eyeglass cleaner, earplugs, and lockout tags.

The assessment of wear and tear on the pockets showcased their robust performance across the three lining fabrics and PE (polyethylene) foam. No color or staining transfer was observed from the exposed surface fabric to the backside of the pockets. While the bottom PE foam experienced some deformation, decreasing in width by 4mm at the lowest point from its original 8mm width, this was attributed to both the damage at the bottom of the bag and the accumulation of dirt, resulting in a slight brown discoloration. Overall, the pockets demonstrated durability, effectively maintaining their integrity despite prolonged use and challenging conditions.

Zipper and Closure Assessment 

The utilization of YKK Aquaguard zippers in both internal and external compartments has been effective in barring the entry of water and dust, underscoring their reliability. However, observations noted some misalignment of zipper teeth, leading to difficulties in fully re-zipping the bag. Additionally, there was a slight color change in the zipper tape, along with loose threads and abrasion from the inside of the fabric adjacent to the zipper tape. These latter issues may be attributed to the weight of Jacob’s bag of hand tools carried on a day to day basis with the vast majority directly against the back of the bag in the laptop/tablet pocket.  Notably, the zipper slider experienced significant wear, resulting in the complete removal of plating in certain areas, while the carabiner pull, although intact - beyond the known issue with breaking closures - lost its coating over time.

The overall durability and smooth operation of the zipper were adversely affected by the uneven distribution of weight within the bag. The concentration of weight, particularly in the laptop/tablet pocket, led to misalignment of zipper teeth, resulting in them coming undone even after fully closing the bag. This repeated issue may, over time, contribute to the dulling of the zipper teeth and create challenges in maintaining secure closure. The heavier load in the "tech" section, housed in a relatively thinner pocket compared to the more spacious "bag of holding" middle pocket, likely contributed to accelerated wear, abrasion, and eventual opening of the zipper pulls.

YKK Aquaguard zippers, originally designed for water resistance, demonstrated versatility in safeguarding against both water and dust, further contributing to the backpack's robust performance. Jacob clarified that the dirt and dust observed on the lining of the bag resulted from regular handling and contact with his hands during work. These findings collectively highlight the zippers' effectiveness in maintaining the backpack's integrity against external elements, while also shedding light on potential challenges arising from specific usage patterns.

Internal Foam Assessment 

The PE foam positioned at the bottom of the backpack, while exhibiting signs of wear and dirt accumulation, has preserved a substantial portion of its original thickness, providing valuable insights into its durability. The initial thickness measures 8 mm across, with the worn section registering 4mm at its lowest point.

In assessing comfort and support, the right shoulder strap displayed slight abrasion and surface fuzzing on the binding and Repreve material. The molded EVA (Ethylene-vinyl acetate) foam cubes within the strap exhibited slight compression, while the mesh on the strap's bottom began to experience abrasion without significant changes in structural integrity. 

Examining the back vented areas revealed compression of the molded foam, altering its cross-sectional shape from a triangle to more of an oval. The mesh in these regions underwent a substantial color change.

The PE foam's resilience was rigorously tested, demonstrating signs of wear at the lowest point. Despite this, it maintained its structural integrity, showcasing resilience over extended use, even when subjected to challenging conditions. These assessments collectively provide a comprehensive understanding of the internal foam's performance, highlighting areas of wear, potential comfort implications, and the enduring structural integrity of critical components.

User Feedback 

Jacob's comments provide valuable insights into the real-world performance of the backpack, offering a user-centric perspective. The robust straps were a huge selling point for Jacob as this is a common failure point for his previous bags that are not LTT, and the reinforced handle with rivets showed no signs of wear on the repreve fabric as well - even when holding up over 8 pounds of tools - as well as a variety of other items - when hooked onto a clamp suspended freely. 

Results and Conclusion

In summarizing the findings from the evaluation, several positive aspects emerge, including the backpack's robust construction, effective material durability, and versatile design. However, areas for potential improvement include observations related to the type of foam, wear on certain components, and changes in the color and structure of specific materials.

The comprehensive evaluation of the LTT Backpack yields a commendable overall performance rating, highlighting its notable strengths in strength and durability across various components. However, the discerned areas for improvement contribute to a nuanced assessment, recognizing both existing merits and opportunities for enhancement. One notable consideration involves the PE foam, which, despite demonstrating resilience, could undergo further testing. An alternative such as EVA molded foam might be explored, potentially offering improved resilience and resistance to compaction over extended periods. This recommendation aims to elevate the backpack's performance by addressing specific areas identified during the assessment, contributing to a continuous refinement of its design and functionality.

Concluding with recommendations for potential users, particularly those working in underground coal mines, it is suggested that the LTT Backpack is well-suited for demanding environments. Its reinforced construction, ample pocket capacity, and resilient materials make it a reliable choice for individuals facing rigorous conditions. Additionally, users are advised to be mindful of potential stress on zippers and adhere to recommended load capacities to optimize the backpack's performance and longevity.