As a leading tank car lessor, it is our obligation to deliver railcars that fit the specific needs of our customers. One such opportunity recently presented itself when a customer transporting molten sulfur asked us to design and deliver rail tank cars. Our experienced team was excited and ready to execute; focusing to ensure all transport and loading/unloading requirements were met along with delivering a safe and easy-to-use design.

Sulfur is a pale yellow crystalline solid and in its molten form is a liquid. Sulfur must be transported in a molten state, otherwise it crystallizes and cannot be loaded or unloaded. The challenge is to keep its liquid state because the melting point of sulfur is around 115°C. Railcars are typically filled with molten sulfur at approximately 150°C and must maintain a minimum temperature of 120°C during transport.

Oliver Behrens, Technical Development Officer at GATX Rail Europe and his team are responsible for new build projects. Oliver said, “Even with our extensive experience, we still come across interesting product transport challenges… like molten sulfur.”

“In designing the customized car type 2741, our core objective was to keep the product temperature steady during the transport and take all precautions to make loading and unloading as easy as possible for our customer,” added Oliver. He continued to explain the key elements,

• Extra Insulation
  To reduce the temperature loss to a minimum during transports, the team added an extra 15cm layer of insulation in addition to a regular cars 10cm
• Eliminate Cold Bridges
  Any component that may be a source of thermal bridges, such as the understructure of the tank wagon, are covered with a layer of thermoplastic material to reduce heat transfer from the tank (product) into the environment
• Heating
  In cold winters or during unforeseen delays, the optimized tank heating allows to keep the Sulfur above the critical temperature of around 115°C. Even the suction cup and the rising pipe are heated for easy top unloading and avoid crystallization of the sulfur during the loading/unloading process.

Oliver added, “This goes to show that no matter the product, we will find a way to transport it. We listen and understand our customer’s challenges and find an optimized railcar design that perfectly fits their needs.“