When Montreal was the busiest seaport in North America outside New York, despite being 1,000 miles from the sea, it was dependent on the value the Great Circle Route that enabled ships from Western Europe to plunge into the heartland of consumer-rich North America.

Of course, that's not been true for 40 years, largely because of the increase in ship size, after which Montreal's 35-foot deep navigation channel was not nearly enough to accommodate ships that required 50-feet. Not only alongside, but throughout that 1,000 miles from the sea.

Then another advantage at one time proved to be a disadvantage a few years later. It had always been good to have piers close to population centres because that shortened expensive overland transit to customers. That put docks and dockers' homes close together worldwide.

But that no longer suited the capital intensive containerised world that took over from the 1970s when most cargo was no longer sold to the affluent in the immediate vicinity, but to far-away more numerous yet less affluent customers in distant cities and towns.

And as ships grew larger and the crews grew smaller, as labour-saving devices saved the cost of labourers, goods could be sold more cheaply and cheaper goods could be sold more widely, which prompted more goods to be made, introducing economies of scale worldwide.

Into the 1970s, the transatlantic trade was the biggest by far. When 500-TEU ships were the only cellular vessels afloat and were few and far between, World War II Liberty and Victory ships dominated the general cargo trade - 99 per cent of which was break bulk.

The joy of the Great Circle Route was that it took cargo into the heart of consumer rich North America at a time when only the affluent could afford imported consumer goods.

Before the opening of the St Lawrence Seaway in the late 1950s, Montreal had been the head of inland navigation for centuries. It was road and rail to points west. But after the Seaway opened, it meant Toronto, Upstate New York, places like Buffalo, Rochester and Syracuse, and then Cleveland, Ohio and their rich densely populated hinterland became open to ocean-going ships, as was Detroit and even Chicago.

Gloomsters and doomsters in Montreal said the end was nigh, that the Seaway meant the port was no longer the head of inland navigation and could be bypassed.

But this turned out not to be true as it took time before shipping habits of centuries changed and by the time they did, shipping itself had changed to make the prospects of the St Lawrence Seaway much less fearful to one party while much less hopeful to another.

By the 1990s, when containerisation was in full swing, ships were getting too big for Montreal. As the average containership size was in the 10,000-TEU range, and Montreal could only dock 4,000 - 3,500-TEUers, it limited the scope of Montreal prospects - especially if one added the cost of ice-strengthening hulls. Only Russians and Norwegians could do that routinely,

What revives the Great Circle Route and the Seaway's relevance today is two developments: 1) The worldwide cargo logjam, 2) the abundance of old panamax ships ideal for the Seaway trade, 3) the rising tide of environmental regulation which makes shipping life more difficult and expensive.      

Much has been revealed in the response to the Covid crisis. Before the lockdown, a small containership carried containers between the Port of Antwerp and the Port of Cleveland on Lake Erie. "That service suggests the future potential for container shipping on the Seaway, despite earlier market failures many years ago," noted Harry Valentine, writing in Fort Lauderdale's Maritime Executive.

Unappreciated by the Maritime Executive article, is the upshot of the global cargo logjam, and the realisation that lessons of yesteryear may well apply to the here and now. Just as cargo handling abandoned the east end London docks and the finger piers of Manhattan, one might see these latest developments repeat themselves as a global phenomena. If concentration is the problem, then the traditional response has been dispersal. What was true of yesteryear may well be true today.

If we picture the supply chain as a series of pythons having to regularly devour an occasional deer, the problem becomes clearer. It is now understood that these are not problems limited to gateway ports. Rail yards and truck depots worldwide - all part of our imaginary supply chain python - with the greatest difficulty must digest and excrete these regular, indigestible large cargo concentrations.

Perhaps in microcosm, the St Lawrence Seaway indicates a way out. That is to treat shipping much in the way DHL, FedEx or even the post office deals with parcel delivery. Perhaps, bigger is not better and the number of 24,000-TEUers has seen its day destined to share the fate of an increasingly rarely needed role of battleships or aviation's supersonic transports.

When coupled with stricter environmental regulation, with its rising compliance costs of cleaner fuel, one must acknowledge the disappearance of cost savings that have been gained from rising ship sizes. And in doing so, one hardly sees the advantage of putting to sea elderly pananmaxes to fit the smaller locks of the Seaway - at least in the short term.

What would makes sense of this is a reliance on technology to rescue the situation. Yes, ships would be smaller, resulting in higher slot costs. But if ships were delivering cargo to where it wanted to go - DHL, FedEx style - smaller and more directly useful ports, this would produce cost savings to cover cost increases resulting from loss of lower slot costs provided by the mega ships.

These cost savings - to compensate for the losses in deploying smaller ships - must be found elsewhere. Automating ports, putting them on a 24/7 work-week. Fuller and more widely applied automation at every level is to be expected as it is continuing here and there anyway. If ship loads are pre-sorted for box destination, so will the yard and terminal space. One can expect fewer mix-ups at collection points because there will be fewer boxes for truckers and railway freight handlers to sort.

Perhaps, with rare exception, the era of the big port is passing with smaller ships serving smaller less socially intrusive ports. So rather than having a python devouring the occasional elephant, cargo might now flow more smoothly in smaller amounts to keep the cost of stock keeping items down to where normal people with normal incomes can afford them.

Or as Mr Valentine of Maritime Executive puts it: "While earlier containership operations along the St Lawrence Seaway faltered, the precedent of successful containership operations between Port of Cleveland and European ports suggests possible equivalent future success involving the Port of Hamilton [Ontario]. Containerships that sail the world’s oceans at the present day are much larger than during the era when container shipping along the St Lawrence Seaway came to an end."