It is sometimes said that much of the technology used for the Panama Canal was developed digging the Chicago Sanitary & Ship Canal during the 1890s—for which a greater volume of earth was moved. The Chicago canal and the machinery used for it was well covered by Scientific American and the engineering periodicals of the day.

I'm a bit late to the party, but I do know that Dutch dredgers were ordered and used during the construction of the Panama Canal. Dutch dredging was making a name for itself in the period of 1870-1914: the construction of the Nieuwe Waterweg was a monumental feat of Dutch engineering. The necessity to keep the Waterweg up to date, because of constantly changing technology - ships getting bigger, more cargo, etc, added with the fact that Rotterdam kept building new ports with the use of dredging meant that local dredging was in constant demand. It has been said that without steam power, the Dutch nation would've turned into a poor overpopulated backwater. Steam power made possible the earliest dredgers. That's 'where' modern dredging starts.

Some of the companies that were involved in constructing the Nieuwe Waterweg are now hired for the big update to the Suez Canal. Van Oord is one of those. One of the biggest differences between Dutch dredging companies and the rest are that most states had a national dredging company while the Dutch were privately held companies. A constant local demand for dredging paired with a rapidly changing world that demanded ever bigger boats to move ever increasing amount of goods meant that ports needed deeper waters and other things that could be realized through dredging. But the dredging companies did not necessarily build dredging ships: Gusto, a Dutch ship yard located in Schiedam, had delivered dredgers to the builders of the Panama Canal in the first decade of the 20th century. Their 'special expertise' were dredgers and they were ordered from all over the world: I've read the diary of a man who went to Thailand in 1955 to oversee the assembling of a dredger there.

That same man had been working for Gusto since the '20s and actually ended up working his entire life for Gusto. Other ship yards here see the same pattern up until the late '60s and 70's. You'd roll into the company at a young age, go through the company's craft school (they had their own schools yes) and then learn more on the work floor. Work hard, show talent and you could climb the ladder. Working your entire career for one company wasn't anything special at the time. The result is that expertise was passed on from one generation to another while giving the company the technical know-how to tackel on new problems. It is also in the 50s that you see that workfloor relations start to change, with bosses being told by workers that their plans weren't right and in need of change. Perhaps not too relevant for your question, but I've seen a vast difference in the relationship between boss/worker in the periods before and after the 2nd World War.

To come to a conclusion of sorts, dredging was a combination of expertise, experience and inventiveness. A company needed to be able to adjust to new circumstances with every job and for that, experience and know-how is a must. The books I've read mention that the real competition for the Dutch dredgers were either local companies (can't compete with them because of towage costs and so on) and US companies - that's why I think that this Dutch-centric story might help you a little.

I certainly don't know all there is to know about it, but if you got further questions, do ask. I'm researching the topic as we speak, so maybe your questions might help me further my own research :)