DW-10 Bottom Dump Wagon Details

[MikePhua]

DW-10 Wagon Background
The DW-10 was a bottom dump wagon (also called a bottom dump or “belly dump” wagon) used in conjunction with older Caterpillar DW-10 tractor/scraper equipment in the mid-20th century. Caterpillar (originating from the merging of Holt and Best, formally J.I. Case etc.) built many large earthmoving and hauling machines; the DW-10 series was part of their early large-tractor line, developed during/after World War II, known for scrapers, bottom dumps, and hauling equipment. The Wagon (sometimes called “bottom dump wagon” or “W10 Wagon”) was designed to fit with those large tractors or scrapers to efficiently dump material through doors or panels in its belly instead of tipping.

Terminology

• Bottom dump (belly dump): A wagon or trailer design that opens underneath (in the bottom) to release load, instead of tilting back/top dumping.
  
• Struck vs. heaped capacity: «Struck» means filled level to the top without heaping; “heaped” means material mounded above the sides.
  
• Gauge: The distance between wheels left-to-right (i.e. track or wheelbase width).
  
• Wagon tare weight: The empty weight of the wagon.
  
• Wagon dump doors / belly doors: Mechanisms (doors, gates) in the bottom of wagon that open to let material out under gravity.
  

Specifications & Known Data
From surviving sales literature, user recollections, and preservation sources, here are the known spec values for the DW-10 bottom dump wagon / “W10 Wagon” that worked with DW-10 tractors:

• Capacity:
  • Struck: ~ 8 ⅓ cubic yards
    
  • Heaped: ~ 11 cubic yards
    
• Empty weight (tare): approximately 10,350 lbs (≈ 4,695 kilograms)
  
• Loading height: about 80 inches (~ 2.03 meters) from ground to wagon bed when loaded or at top of sides for loading
  
• Compatibility: Designed to be hauled or towed behind DW-10 tractors; sometimes fifth-wheel type mounting between tractor and wagon frame.
  
• Series variations:
  • Early series (“1N”) in early 1940s with approx. ~ 15,180 lbs for the tractor alone, gauge ~ 68 inches with large rear tires ~ 18×24.
    
  • Later series (“6V” and “1V”) increased power (engine changes), slight changes in weight, tire sizes etc.
    

Issues & Restoration Information

• Some wagons have been modified over the years. One example: a DW-10 with a bottom dump wagon had a modern style water tank built over the entire wagon, attaching only at front and rear structural members, which complicated restoration.
  
• Original dump (belly) doors are often missing; restorers seek specifications or pictures to fabricate or restore the doors.
  
• The wagon construction often included braces in the rear, and varying styles (square backs vs curved, etc.), making precise replication challenging without good reference material.
  

Comparisons & Context

• The DW-10 Wagon worked with DW-10 scrapers; in the same era the scraper (“No. 10” scraper) had capacities roughly similar (e.g. ~ 8-9 yds struck, ~11 yds heaped) when updated in 1950s.
  
• The DW-10 tractor evolved through several series (1N, 6V, 1V), with engine power rising (from ~ 90 hp to ~ 115 hp), changes in tires, transmission, etc.
  

Challenges in Restoration & Suggested Solutions
Given the age, rarity, and frequent modifications/missing parts, anyone restoring a DW-10 bottom dump wagon should consider the following:

• Gather good references: old sales catalogues, photos, original drawings. Because belly doors (dump doors) are often missing, you’ll need diagrams to recreate them with correct hinge points, door locking, mechanism to open bottom reliably.
  
• Structural integrity: Check frame members (front, rear, side rails, undercarriage) for rust, weld fatigue. Wagons are often left exposed, causing corrosion, which weakens structural members. Reinforcement with matching steel where necessary.
  
• Fabrication of missing components: Doors, hinges, actuator rods. Use steel of similar thickness and strength; replicate door supports (braces) as in original design (square or triangular supports). Ensure doors seal well when closed to avoid spillage during travel.
  
• Weight balance & towing alignment: Since wagon empty weight is ~10,350 lbs, ensure hitch/fifth wheel or drawbar is aligned; misalignment can cause wear or structural stress. Also ensure load distribution when full avoids undue overhang or ground pressure.
  
• Hydraulic or mechanical door actuation: If original was mechanical (lever, chain, linkage) consider whether to restore original style or retrofit with more modern mechanical/hydraulic systems—but maintain safety and period correctness if that is a goal.
  
• Safety & legal compliance (if used on roads): Brakes, lighting (if required), reflectors or markers—many old wagons never had road-legal lighting, so if the wagon is moved on public roads, these may need to be added. Also weight limits.
  

Data & Estimations

• If fully loaded (11 cubic yards heaped), depending on material density (say loose earth or aggregate at ~2,500 lbs per cubic yard), gross loaded weight might approach ≈ 27,500 lbs (~12,470 kg) plus wagon tare (~10,350 lbs) plus tractor weight, pushing total rig weight significantly.
  
• Dimensions: From reports, the tractor in 1V series is ~15 ft (≈ 4.6 m) length,wagon body adds more. Overall rig length with bottom dump wagon could exceed 35 ft (≈ 10.7 m) in many cases. Width around 7′-8′ (≈ 2.1-2.4 m), height maybe ~5′-6′ (≈ 1.5-1.8 m) empty, more when full.
  

Stories & Anecdotes

• A restorer in Minnesota once encountered a DW-10 bottom dump wagon that had been converted into a water tanker with a tank welded over the bed; the bottom dump doors had been removed decades back. The restorer’s challenge was to cut off the tank without damaging the original wagon structure, locate or recreate doors, hinges, bottom panels, and restore period correct dimensions.
  
• Another owner noted that in early Dw10 wagons, the bottom dump wagon was sold as a factory option (Cat built or contracted), and some units had serial plates or data tags that helped identify the wagon model. When restored, those detail tags often fetched more collector interest at vintage-equipment shows.
  

Recommendations for Preservation / Use

• If acquiring a DW-10 wagon, check for intact door frame, support braces, original steel thickness, serial numbers. Document everything.
  
• Store under cover to slow corrosion, especially on belly panels and door hinges.
  
• Fabricate replacement parts before using on rough ground; original belly doors that are damaged or missing often cause safety hazards or operational issues (material dumping unexpectedly).
  
• Use lighter load densities if towing over public roads to obey weight limits; possibly reduce heaped load to stay under legal hauling weight.
  
• For show/restoration use, try to source or reproduce the original paint, decals, signage to enhance historical fidelity.
  

Conclusion
The DW-10 bottom dump wagon (W10 Wagon) is a rare, historically significant implement paired with the Caterpillar DW-10 tractors. Capacity ~ 8⅓ yds struck, ~ 11 yds heaped; empty weight ~ 10,350 lbs; loading height ~ 80 in. While many units have been modified, missing doors and structural wear are common. Restoring one to original condition takes research, fabrication skill, and careful structural work. For those interested in antique machinery or historical preservation, bringing one back provides rewards both in heritage and in seeing a classic earthmoving tool function again. If planning use beyond display, practical upgrades and safety additions will help.