Butane Coolant - Loading Into Ship's Cargo Tanks

Liquid gas cargoes are calculated and measured in a similar manner to other liquid cargoes such as crude oils and petroleum products. However, liquefied cargoes are specially carried in a closed/confined system and the vapor quantity has to be measured when calculating the total quantity on board.

Butane is a gas that quickly vaporizes at room temperature and atmospheric pressure. It is a highly flammable, colourless, and easily liquefied gas. However, in order to be stored, it requires to make a liquid form which is brought about under an average pressure.

The cargo of butane is commonly stored in cylindrical or spherical storage tanks with very low pressure. Bullet tanker trucks are used to carry the Butane cargo under pressure within the capacity due to smaller size and gauging level indicators that are fitted with the bullet tanker trucks to display the cargo volume, carriage temperature, and pressure. At the loading or discharge port or terminal, the surveyor should inspect prior to loading or discharge the cargo from the ship's cargo tanks.

During loading or discharging operation supervised by our staffs survey or at Constellation Marine Service of the liquefied gas cargo, the ship's personnel are required to maintain the safety considerations such as not to carry matches or lighter, mobile phones are strictly prohibited, smoking also restricted or prohibited, normal communication equipment is not to be used if it is certified, and hot work, hammering, and chipping tools are also prohibited during the time of loading/discharging.

During the course of loading/discharging the liquefied cargo, normal spillage or leakage is also noted on board in form of liquid or a leak of vapor through the hose connection. Co-ordination must be maintained regarding the discharging / receiving flow of cargo with an agreeable rate of temperature and pressure between the ship's and shore personnel during the operation. Recently, we the undersigned surveyors carried out the loading of Butane coolant in the ship's cargo tanks from 4 nos. of Bullets tankers trucks at the port. These bullet tankers were inspected by us prior to and post-loading operation and the operation went off well without any issues/discrepancy.

We, at Constellation Marine Services LLC, as independent ship & marine surveyors, often get nominations from our new and existing clients to carry out loading of butane coolant survey, prior loading the cargo into ship's nominated cargo tanks and inspection of 4 nos. of Bullet tankers trucks prior to loading operation from commencement till completion without any unwonted situation occurred during the survey.

Mr. Sumanta Kumar Tarai

Mr. Ouseph Joshi