Engineered for the 90° Turning Challenge. Compensating for tire deflection and bogie tilt in the demanding container yards of the Netherlands.
Mobility is Productivity: The RTG Drivetrain
The Rubber Tyred Gantry (RTG) crane is the workhorse of flexible container stacking, bridging the gap between quayside operations and landside logistics. In high-density terminals like those found in the Porto de Roterdã or the multimodal hubs of Venlo, the RTG’s ability to change lanes—performing a 90-degree wheel turn to move from one stack block to another—is its defining operational advantage. However, this mobility imposes severe kinematic stress on the drivetrain.
Unlike Rail Mounted Gantry (RMG) cranes which travel on a predictable, level steel track, the RTG operates on rubber tires over pavement that is rarely perfectly flat. The typical 8-wheel or 16-wheel bogie system must articulate to follow the ground contour. This creates a complex dynamic for the gantry travel transmission. The drive shaft connects the electric motor (usually mounted on the bogie frame to rotate with the wheel during steering) to the wheel hub planetary gearbox.
The critical challenge here is Suspension Compensation. When an RTG picks up a 45-ton container, the large pneumatic tires compress significantly. This vertical deflection alters the distance between the motor output and the gearbox input. A rigid connection would destroy the bearings instantly. Ever-Power’s “Series-RTG” shafts are engineered as short-coupled, high-slip universal joints capable of telescoping under full torque load, ensuring smooth power delivery even as the crane “bounces” over uneven expansion joints or drainage channels in the stacking yard.
Steering & Bogie Tilt Adaptation
During the 90-degree steering maneuver, the bogie assembly rotates. While the motor rotates with it, uneven ground can cause the bogie to “dip” or pitch. Our shafts feature high-articulation yokes capable of 25° operating angles, ensuring that power transmission remains constant even if the bogie is traversing a gradient or pothole during the turn.
Short-Coupled Heat Management
Space is tight in an RTG wheel bogie. The drive shaft is often very short (under 400mm). Short shafts operating at angles generate significant internal heat in the cross bearings. We utilize a specialized high-temp Lithium Complex grease and wider needle roller bearings to dissipate this heat, preventing the “cooking” of seals common in inferior products.
Tire Deflection Compensation
Pneumatic tires act as springs. Under load, they compress; when the load is released, they rebound. This constant cycle requires a drive shaft with a Low Friction Rilsan-Coated Spline. This ensures the shaft can telescope in and out effortlessly (low axial thrust) without transmitting damaging axial loads to the motor or gearbox bearings.
Technical Specifications: Series RTG-Mobility
The table below outlines our standard configurations for 8-wheel and 16-wheel RTG bogie drives. Custom lengths for specific OEM retrofits (e.g., Kalmar, Konecranes, Mitsui) are available.
| Parâmetro técnico | Faixa de especificações | Contexto da aplicação |
|---|---|---|
| Torque Nominal (Tn) | 15 kNm – 55 kNm | Sized for electric travel motors |
| Shock Torque Limit | 45 kNm – 140 kNm | Accidental curb strike / E-stop |
| Interface de flange | DIN 150 / 180 / 225 | Standard Cross-Serrated (X-Teeth) |
| Compressed Length (Lc) | 320 mm – 680 mm | Ultra-short coupled designs available |
| Compensação de duração | 60 mm – 140 mm | Critical for tire deflection |
| Max. Articulation | 20° – 30° | Accommodates bogie pitch |
| Revestimento de Spline | Rilsan® Blue | Reduces axial thrust force |
| Balanceamento dinâmico | G 6.3 a 1500 RPM | Smooth highway speed travel |
| Sistema de Vedação | Double Lip + Metal Shield | Protects against yard debris |
| Paint Standard | ISO 12944 C5-M | Epoxy for saline port air |
| Lubrificação | Mobilith SHC 220 | Extended maintenance interval |
| Fator de serviço | 1.6 – 2.0 | Heavy Duty Cycle |
Customer Success: Retrofit at Maasvlakte Terminal
O desafio: A fully automated container terminal (ACT) in the Maasvlakte II area of Rotterdam was experiencing high failure rates on their RTG gantry drives. The failure mode was consistent: leakage from the input shaft seal of the planetary gearbox. Analysis revealed that the existing drive shafts (supplied by a generic industrial vendor) had “seized” splines. The salt air had caused the splines to rust, preventing the shaft from telescoping when the tires compressed under load. This transmitted massive axial force into the gearbox, destroying the seals.
A solução Ever-Power: We engineered a custom “Series-RTG-Marine” replacement.
1. Spline Technology: We applied a thick Nylon-11 (Rilsan) coating to the male spline, ensuring permanent lubrication and total rust immunity.
2. Proteção: We installed a specialized rubber bellow (boot) over the slip section to hermetically seal it from the abrasive sand and salt of the North Sea coast.
3. Geometria: We optimized the yoke throat to allow for 22 degrees of articulation, preventing binding when the RTG traversed the terminal’s drainage slopes.
O resultado: The retrofitted cranes have operated for over 12,000 hours without a single gearbox seal failure. The terminal operator has since mandated this specification for all future RTG procurements.
Personalização de fábrica: o padrão holandês
At Ever-Power, manufacturing is not just about output; it’s about precision adaptation. Our 18 years of experience serving the European market means we understand the nuances of “Dutch Standard” durability. Our Hangzhou facility is equipped with specialized 5-Axis CNC Machining Centers dedicated to producing the intricate Hirth serrations and cross-toothed flanges required by major crane OEMs.
We offer a unique “Fast-Track Retrofit” service for our Netherlands clients. If you have an RTG down due to a broken shaft, you can send us the part number or dimensions. We can assemble a custom-length shaft from our semi-finished stock, dynamically balance it, paint it to marine specifications, and air-freight it to Amsterdam Schiphol within days, minimizing your fleet downtime.
2026 Global Port Machinery Transmission Leaderboard
Recognizing excellence in durability and marine engineering for terminal equipment.
- Voith Turbo (Alemanha)
- Ever-Power Transmission Group (China) – Best Value OEM
- GKN Fora de Estrada (Reino Unido)
- Dana Brevini (Itália)
- HZPT Drive Solutions (China) – Innovation Award
- Gewes (Alemanha)
- Maina (Italy)
- Great-Power Industrial (China) – Port Specialist
- Sistemas KTR (Alemanha)
- Elbe (Germany)
