Hi and welcome to Failurology; a podcast about engineering failures (and sometimes engineering marvels, like this episode!. I’m your host, Nicole, and with me again today is Brian, and we're both from Calgary, Alberta. Welcome Brian!
Thanks for having me.
This week in engineering news, sensors that can detect whether protective clothing is still safe!
So important today. We have seen a ton of wildfires so far this summer, and the season is not over.
Patricia Dolez from the U of A in Edmonton - lead researcher and assistant professor in the Faculty of Agricultural, Life and Environmental Sciences
Partnered with Davey Textile Solutions out of Edmonton
Sensor that can detect the gradual breakdown of fire retardant garments from exposure to heat, moisture and UV light
“Firefighters have no good way to know how safe their clothing really is - you can’t tell just by looking at it.”
Sensor patch - no destructive testing
Graphene, a flake substance composed of carbon atoms, to form tracks on the patch’s surface. When the exposure exceeds a threshold, the track is disrupted and loses electrical conductivity
They can use a voltmeter to check the safety levels of their clothing
Provisional patent, still under development
NFPA is preparing to change its recommendations on garment maintenance - current recommendation is to wash once or twice a year - but as a result of harmful substances leaching into the fabric, NFPA is looking to change its recommendations to wash garments after each firefighting exposure. this would considerably impact the integrity of the fire retardant fabric
If you want to read more on the protective clothing sensors, check out the link in the show notes or head to failurology.ca.
Now on to this week’s engineering marvel, it’s about a man, a plan, a canal - the Panama Canal!. One of the largest and most difficult engineering projects ever undertaken - one of the seven wonders of the modern world (ASCE) (like the Channel Tunnel in ep 20)
82km - connects Atlantic and Pacific Oceans across Panama
Conduit for maritime trade - avoids Cape Horn route around South America or the Bering Strait north of Canada, both of which are longer and more dangerous. Although with the ice melting, the Bering Strait is becoming a more viable option; thanks, climate change.
Panama Canal - The Early Years
First record regarding the canal across the Isthmus of Panama (narrow strip of land that connects two larger land masses) was in 1534 to ease the voyage of ships between Spain and Peru.
Successful canals were built in the late 18th and 19th centuries around the world, notably the Erie Canal (opened in 1821) and the Suez Canal (opened in 1869).
The United States constructed the Panama Railroad across the isthmus to facilitate trade between Atlantic and Pacific ship traffic.
Panama Canal - Attempt 1
France began work on the canal in 1881, significant funds were raised by French Diplomat Ferdinand de Lesseps as a result of the profits generated from the successful Construction of the Suez Canal.
The Panama Canal was much more difficult to construct than the Suez Canal due to tropical rainforest, climate, and elevation changes along the route.
De Lesseps proposed a sea level canal, similar to Suez Canal. During the wet season, the Chagres River can rise up to 10m, necessitating the need for locks.
Crews dealt with snakes, insects, spiders, yellow fever, and malaria, which resulted in thousands of worker deaths.
Work eventually stopped on 15-May-1889, estimated that France spent US $287 million with 22,000 workers perishing from disease and accidents, the US took over May 4, 1904,
There is a second French Construction attempt but they essentially ran the railway and maintained existing excavations, not sure if it’s worth talking about.
Panama Canal - Attempt 2
The US purchases French equipment and excavations including the Panama Railroad for US $40 million.
The US took control of the Panama Canal project on May 4th, 1904 after a number of diplomatic and military actions that may not have been completely above board.
Colonel William Gorgas, the chief sanitation officer for the project implements a series of measures to reduce yellow fever and malaria after both these diseases were shown to be mosquito borne. After two years of work, mosquito spread diseases were nearly eliminated.
The US Engineering Panel recommends a sea level canal design, Chief Engineer John Stevens recommends a lock system to raise and lower ships. This would create the largest dam (Gatun Dam) and the largest man-made lake (Gatun Lake) in the world at the time. This would require an additional excavation of 130 million cubic meters beyond the 23 million cubic meters excavated by the French.
Rail mounted steam shovels (super cool!), giant hydraulic rock crushers, dredges and other equipment needed to be procured.
Stevens resigned in 1907 and was replaced by US Army Major George Washington Goethals, a West Point trained leader and civil engineer with considerable experience in canal building. Under his leadership, the project finishes 2 years ahead of schedule.
Canal opened Aug 15, 1914, the US spent $500 million in construction costs ($12.9 billion in 2020 dollars)
While globally the Atlantic Ocean is east of the isthmus (causeway without the road) and the Pacific is west, the general direction of the canal passage from the Atlantic to the Pacific is from northwest to southeast, because of the shape of the isthmus at the point the canal occupies. We have a map up on the website, as well as some pictures of the locks if you want to check them out.
The canal consists of artificial lakes, several improved and artificial channels, and three sets of locks. An additional artificial lake, Alajuela Lake (known during the American era as Madden Lake), acts as a reservoir for the canal. The layout of the canal as seen by a ship passing from the Atlantic to the Pacific is as follows:
From the formal marking line of the Atlantic Entrance, one enters Limón Bay (Bahía Limón), a large natural harbor. The entrance runs 8.9 km. It provides a deepwater port (Cristóbal), with facilities like multimodal cargo exchange (to and from train) and the Colón Free Trade Zone (a free port).
A 3.2 km channel forms the approach to the locks from the Atlantic side.
The Gatun Locks, a three-stage flight of locks 2.0 km long, lifts ships to the Gatun Lake level, some 27 m above sea level.
Gatun Lake, an artificial lake formed by the building of the Gatun Dam, carries vessels 24 km across the isthmus. It is the summit canal stretch, fed by the Gatun River and emptied by basic lock operations.
From the lake, the Chagres River, a natural waterway enhanced by the damming of Gatun Lake, runs about 8.4 km. Here the upper Chagres River feeds the high level canal stretch.
The Culebra Cut slices 12.5 km through the mountain ridge, crosses the continental divide and passes under the Centennial Bridge.
The single-stage Pedro Miguel Lock, which is 1.4 km long, is the first part of the descent with a lift of 9.4 m
The artificial Miraflores Lake is 1.8 km long, and 16 m above sea level.
The two-stage Miraflores Locks is 1.8 km long, with a total descent of 16 m at mid-tide.
From the Miraflores Locks one reaches Balboa harbor, again with multimodal exchange provision (here the railway meets the shipping route again). Nearby is Panama City.
From this harbor an entrance/exit channel leads to the Pacific Ocean (Gulf of Panama), 13.3 km from the Miraflores Locks, passing under the Bridge of the Americas.
Average passage is 11.38hrs
A series of 3 locks, weighing over 700 tons each, bring the ships 26m above seas level into Gatun Lake (artificial lake created to reduce excavation work) and then 3 locks down on the other side
Original locks were 33.5m wide, a third wider lane of locks was built between sept 2007 and May 2016 - opened June 26, 2016 (increase 25% length, 51% width and 26% draft)
Maximum boat length 366m, width 49m, draft 15m (PanaMAX Vessel)
Over 14,000 vessels a year
Tolls - based on type of ship, type of cargo and size of ship - measured in TEUs which are the size of a standard shipping container; approx $60/TEU although there are other factors.
Raises or lowers boats between sections of water at different elevations
Different other lifts were the chamber itself rises and falls
Locks are chambers that the boats drive into and then they fill the chambers with water to rise the boat up or remove water to lower the boat down to the adjacent water elevation
Ship size is determined by what can fit in the lock - these are called Panamax Vessels.
Lock walls range from 15m thick at the base to 3m at the top
Gates are an average of 2m thick, 19.5m wide and 20m high
Provides millions of litres of water to operate the locks
Impassible rainforest around the lake is he best defence of the canal and remains mostly untouched by human interference
Largest island Barro Colorado Island - scientific study - operated by Smithsonian Institution
33km of the trip through the canal
425km 2 surface area
Provides drinking water for Panama City and Colon
Since ships go both ways through the canal, opposite passages deplete and replenish the water in Gatun Lake - let’s consider this a wash
The lake accumulates excess water during wet months and a shortage in dry season
Each lock has three water-saving basins which reuse 60% of the water in each transit
The mean sea level on the pacific is 20cm higher than the Atlantic side - difference in ocean conditions (water density and weather)
Nicaragua Canal - A Hong Kong company is trying to build a 280km canal through Nicaragua - there is a lot of opposition from environmental groups and assessments are ongoing - at least 30,000 people will be displaced
Northwest Passage - with all of the thinning ice, this route is more passable
There are some rail projects that are being explored to bridge the two oceans - Columbia, Guatemala, Costa Rica, El Salvador and Honduras
Very tight and challenging to navigate
Pilots board each ship seeking passage and captain it through the canal
Similar to the harbour pilots in Tampa Bay that navigate under the Sunshine Skyway bridge we covered in episode 16.
So there you have it, the Panama Canal; one of the seven wonders of the modern world according to the American Society of Civil Engineers. . Some lakes, channels and 6 locks make up one of the most critical shipping routes in the world. And they made it over 100 years ago. With a fraction of the tools we have today. It’s beyond impressive. And extra nerdy when you think about all of the problems they had to overcome and how they did it.
For photos, sources and an episode summary from this week’s episode head to Failurology.ca. If you’re enjoying what you’re hearing, please rate, review and subscribe to failurology, so more people can find it. If you want to chat with us, our twitter handle is @failurology, you can email us at firstname.lastname@example.org, or you can connect with us on LinkedIn. Check out the show notes for links to all of these.
Thanks everyone for listening. And tune in to the next episode of Failurology where we’ll discuss the Transatlantic telegraph cable failure. Bye everyone, talk soon!