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Mechanical Engineering

Engineering Services

Rotating Hoist Deck for an OET Crane

Power Transmission Systems

CP&A has provided designs for power transmission systems for a variety of applications. Systems include but are not limited to hoisting, rotating, and linear travel. Whether it’s a new application, drop in replacement of a single component or a complete redesign CP&A's mechanical engineers can provide solutions.


  • Cranes

  • Aerospace Tooling

  • Hangar Doors

  • Material Handling

Failure Analysis

CP&A provides services to investigate the cause of mechanical failure. After a thorough investigation, our mechanical engineers can offer fixes to prevent the failure from being repeated. Prevention is always preferable to repair or replacement. We believe it is our responsibility to suggest prevention measures.

The example shown was a shaft mounted gearbox with a torque arm. The torque arm was not stiff enough to allow proper shaft alignment under load. The misalignment increased the demand on the shaft, which lead to crack formation and eventual failure.


The trolley drive system was redesigned to have the motor brake and gearbox on a common foundation. The common foundation was fixed to the main structure with a torque arm. This allowed the high speed shaft connecting the motor, brake and gearbox to stay in alignment under load.

Ship to Shore STS Container Crane Trolley Drive Failure
Custom OET Crane Interlock

Custom Mechanical Systems

In the machine design industry, very few applications are ever the same. Sometimes special components needs to be designed in order to meet special project requirements. CP&A have designed custom interlocks to allow a trolley to transition from bridge to bridge for both single girder and multiple girder cranes. Other projects include custom spreader beams, jacking systems to move STS cranes, and a drive system to carefully open an 8,000 lb door for a paint booth.

Custom design is not a separate division, it makes up the majority of CP&A’s design work. CP&A have designed a variety of specialized equipment tailored to our client’s needs. We have experience designing under challenging environments that many shy away from such as Class I Div I hazardous zones.

Redesign and Retrofit

Oftentimes retrofitting older cranes or machines is a better solution than buying a new one. When spare parts are no longer available, our mechanical engineers can design and develop drop-in replacements that can be manufactured by local machine shops.


  • New Load sensing system

  • Container Crane Snag Protection

  • STS Trolley Drive Redesign

    • Original design had repeated shaft failures across multiple cranes

  • New end trucks to extend life on an OET crane

  • RMG Main hoist redesign

    • Original design had repeated gearbox failures across multiple cranes

  • Articulating Gantry System

    • Drop in solution to allow an STS crane traverse a curved rail segment.

  • STS Crane Forestay Replacement

    • Designed a drop-in replacement built by a machine shop local to the client.

  • Trolley Wheels

    • CP&A selected a grade of steel and specified a heat treatment process to help a local manufacturer produce trolley wheels that met the specification.

Hardened Wheels for a STS crane Trolley
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