Load matters: Transporting an 80-ton transformer
by Donna Mun | Sept. 20, 2018
Transformers play an integral role in maintaining service to our customers and keeping our substations up and running. When one of them doesn’t work, there is no alternative but to replace it. It typically doesn’t happen too often, but within a year, Hawaiian Electric has had to deliver two 80-ton transformers — the largest type used at our substations.
Last September, an 80-ton transformer was transported from our Ewa Nui Substation in Kapolei to the Koolau Substation in Kaneohe. And in June of this year, we delivered one from Kapolei to the Pukele Substation in Palolo Valley.
When you hear the word “transformer” your first thought might be of a robotic toy that children alter into vehicles or beasts. But an actual transformer is an oversized piece of electrical equipment that is used to convert energy by increasing or decreasing voltage to supply electricity to homes and businesses.
When a transformer breaks, a replacement must be delivered to the substation. The delivery of an 80-ton transformer — roughly the same weight as 107 cows with an average weight of 1,500 pounds — requires careful coordination.
The heavy load requires a transport vehicle that travels at a speed of 10 to 15 miles per hour on roadways and 5 miles per hour on bridges, avoiding low overpasses and areas where weight limits restrict travel. This means the freeways cannot be used to deliver the transformer from one location to another, especially when traveling across the island. Due to the route and speed, the delivery can take as many as four hours.
The route typically runs through the Ewa area and heads east through Salt Lake to Nimitz Highway. At Waiakamilo Road, the route heads up to Vineyard Boulevard and then travels downtown on Bishop Street to South King Street. If you’re working in downtown Honolulu, you may even catch a glimpse of the transformer passing by as it heads to its final destination.
To make things even more complicated, there are only two trucking companies in the state that are certified to handle the transport of such a heavy load — Yamashiro Trucking and Akana Trucking. And the transport vehicle is also accompanied by Honolulu Police Department (HPD) personnel to escort and safely direct traffic. The schedules of the certified driver and HPD, as well as approval from the Department Transportation, determine the actual date of the transport.
For safety reasons, the delivery is usually done during the day to ensure that any unforeseen issues can be addressed quickly. Last year, during the actual transport, a flat tire on the transport vehicle had to be replaced midway through the route in order to complete the delivery.
The oversized load makes for a challenging delivery, but with the right people and good planning, the transformer arrives safely!
Donna Mun is a manager of digital communications at Hawaiian Electric.
