The group of hardwoods that are suitable for railway sleepers in Nigeria is

The group of hardwoods that are suitable for railway sleepers in Nigeria is "mahogamy, obeche, and iroko". These hardwoods are known for their durability and strength, making them ideal for use as railway sleepers which need to withstand the weight of trains and the harsh outdoor environment. Mahogany is a dense and durable hardwood that is known for its strength and resistance to decay, making it a popular choice for railway sleepers. Obeche is a lightweight hardwood with good stability and strength, making it a good choice for railway sleepers that need to be lightweight yet strong. Iroko is a durable hardwood that is resistant to decay and weathering, making it an ideal choice for outdoor use, such as railway sleepers.