The Panama Canal Expansion - Remarkable Reengineering


In 2014, the year the Panama Canal celebrated its centenary, I wrote an article on this engineering marvel (which can be found over at EIT's sister company, IDC Technologies).  This year the Canal achieved another milestone, the completion of an expansion project which was formally proposed in 2006.

The opening was originally intended to coincide with the Canal’s 100 year anniversary, but as is the nature of projects of this scale, deadlines become slippery. Two more years passed before its completion.

The US$6 billion renovation, or ‘Third Set of Locks Project’, was a necessity. Ships have been steadily increasing in magnitude, but were becoming limited by the scope of the locks – originally conceived in 1881! The project has seen the construction of a new bigger lock and deeper lane near each coast.

The new locks are 427m (1400ft), longer than the existing ones which are 305m (1000ft). The original 34m (111ft) width has been increased by 21m (69ft) and the new channels at 18m (59ft) are 6m (19.5ft) deeper.

Instead of the miter gates used in the extant locks, the more efficient and more robust rolling gates have been fitted to the new locks, as the diagram below illustrates. 

Each lock has three chambers and each chamber has three lateral water-saving basins (nine per lock). These facilitate the raising of the vessels from sea level to the level of Gatun Lake, a whole 26m (85ft) above sea level, before moving back down to the opposite coast.

Gatun Lake (an artificial lake on the Chagres River) has an area of 425km2 (164sq mi) storing 5.2 cubic kilometres (183,000,000,000ft³) of water. This is approximately as much as flows along the Chagres River in an average year.

The ingenuity of the system is that the locks are filled and emptied using gravity and valves (just like the original), without the need for pumps.

The percentage of vessels now able to make the transition has improved with the new lock dimensions. It remains constrained, but is up from 49% of vessels to 79%.

Terms used to describe the vessel size limits for the Canal are Panamax, for the historic Canal and now, after the expansion, New Panamax. (Over time the designs of cargo ships, naval vessels, and passenger ships have all been influenced by these dimensions).

A further bonus is that the vessels needing passage may now be expedited – the delays, particularly between December and March, have sometimes stretched to seven days. It has been projected that with the new locks the Panama Canal has approximately doubled its capacity.

 

Aerial view of vessels waiting at Gatun Lake, before entering the locks to exit into the Atlantic Ocean. On the left of the image the new set of locks are shown under construction.

 

The cynics remain however; there are those who believe that delays will still be experienced by those using the waterway. One of the causes, it is claimed, is a bottleneck through the Culebra Cut where larger vessels are limited from passing one another (even after efforts were made in 1992 to expand it). 

The Culebra Cut is an artificial valley where vessels traverse the continental divide; it was considered one of the great engineering feats of its time. The project involved bringing the level of the land down from 64m above sea level to just 12.

Another delay is caused when very large vessels move through the locks, requiring very careful manoeuvring. This is further exacerbated by having to make the transition during daylight.

The fall out from climate change is another factor that must exercise the minds of Panama Canal’s water resource division. Floods could damage the expensive infrastructure and drought would affect water levels; both pose a very real and negative threat to the efficient workings of the Canal.

In December of 2010 the Canal received a sense of nature’s indifference. The locks were made very susceptible to damage by a deluge of rain, resulting in the Canal’s closure until the waters had subsided. 

The critics’ musings aside, the Panama Canal has been privy to much through the years. The world of shipping has meandered through its waterways for over a century; not merely cutting a corner, but traversing a continent. It is to the inspiring logistics and engineering teams (responsible for the original Canal and now its expansion) that the passing ships’ captains should be doffing their caps.

Thanks very much to all those who contributed to the following articles (including the diagrams and photographs within). Without you this brief reflection on the brilliant re-engineering of the Panama Canal would not have been possible.

https://en.wikipedia.org/wiki/Gatun_Lake 
https://en.wikipedia.org/wiki/Panamax
https://www.theguardian.com/sustainable-business/2014/aug/14/climate-change-panama-canal-water-shipping-closures
https://en.wikipedia.org/wiki/Panama_Canal_locks
http://library.water-resources.us/docs/MMDL/FLD/Feature.cfm?ID=25
http://panamacanalamplification.blogspot.com.au/
http://www.news.com.au/travel/world-travel/central-america/panama-canal-expansion-to-be-completed-this-weekend/news-story/3cfa4a176ee7a20ed6616ca489f4a760