1. General Specifications
triple-axle design for heavy loads
1065 mm (Cape gauge)
Upgraded versions: 1435 mm (standard gauge for cross-border operations)
Axle Load: 26–30 metric tons (up to 35 tons in modified versions)
Design Speed: 80–100 km/h (depending on wagon configuration)
Weight of Bogie: ~7–8 tons (varies by model)
2. Wheelset Details
Wheel Diameter: New: 915 mm (36 inches) Minimum worn: 850 mm
Wheel Back-to-Back Distance:1055 mm (narrow gauge) 1360 mm (standard gauge)
Wheel Material: High-strength alloy steel (compliant with EN 13262 or AREMA standards)
3. Suspension System
Primary Suspension:
Coil springs (6–8 per bogie)
Some models include rubber pads for damping
Secondary Suspension:
Some upgraded versions use rubber springs or air springs (for higher-speed operation)
Damping: Hydraulic shock absorbers (in later models)
4. Braking System
Single-sided cast iron/composite brake shoes
Some variants use disc brakes (MK VII-C)
Brake Cylinder Size: 8–10 inches (203–254 mm)
Lever Ratio: ~4:1
5. Structural Features
Side Frames: Welded steel construction (some use high-strength low-alloy steel)
Axlebox Guidance: Pedestal-type (some models use rubber suspension)
Bearings:
Early versions: Tapered roller bearings (Timken/SKF)
Modern versions: Sealed unit bearings (reduced maintenance)
6. Typical Applications
Ore wagons (e.g., TFR’s 36E series)
Coal hoppers (e.g., TFR’s 45D series)
Adapted for standard gauge (e.g., Mozambique routes)
Variants & Upgrades
| Model | Key Improvements | Axle Load | Gauge Compatibility |
| MK VII (Standard) | Base 3-axle design | 26–30 t | 1065 mm |
| MK VII-A | Reinforced side frames | 30–35 t | 1065/1435 mm |
| MK VII-B | Air spring suspension | 28 t | High-speed heavy haul |
| MK VII-C | Disc brakes + unit bearings | 30 t | 1435 mm |
