By the time of the industrial revolution, Britain already had a relatively sophisticated transportation network. This was partly because of its accommodating waters, but partly because of its coal. As the heaviest and bulkiest of daily necessities, coal was the nation's cutting edge cargo, the one that kept forcing it to find new ways to move things.SOURCE: Coal: A Human History, by Barbara Freese (Penguin, 2003), pp. 85-87
It was noted in the 1600s that "it is the great quantities of Bulksome Commodities that multiplies ships and men," and commodities didn't get more bulksome than coal. And so, as the coal trade grew in the latter half of the 1500s and in the 1600s, so did the nation's shipping fleet. Already in the early 1600s, more ships were used to move coal than everything else combined. England would no doubt eventually have developed its shipping industry without the impetus of the coal trade; but London's growing dependence on coal left it no choice in the matter, and surely accelerated the nation's maritime investment. Once they had built the ships, the ports, the sailing fleet, and the skills required for the coal trade, the English found it much easier to expand their maritime trade to other commodities and other locations. According to one historian, "the coal trade may be regarded, in short, as a magnet which helped to draw Englishmen to seek their profit and their livelihood in ocean commerce."
The expansion of England's private fleet would prove vital not just commercially but militarily, too. Despite being an island nation, England had not always been a maritime power. Henry VIII built its first real Royal Navy, but it was not strong, and in times of trouble, the nation had to commandeer private vessels: Elizabeth I's navy was more powerful than her father's, but even so, it needed the help of dozens of armed merchant ships to defeat the Spanish Armada in 1588. England's coal ships were particularly important for national defense, and by the early 1600s it was axiomatic that the coal trade was the "chief nursery" for English seamen. Although there were more vessels involved in fishing, they were smaller and of less use to the navy. The sturdier coal ships, with their larger crews, were a vital national asset and could be called up quickly when needed. And when called upon, there was no refusing; the coal ships and their thousands of crew members were pressed into service, by force, many times in English history. In fact, in times of war, those involved in the coal trade demanded additional wages because they ran such a high risk of being forced into the navy.
Paradoxically, the coastal coal trade was another reason a navy was so important in the first place. London and the south of England had become dependent on this fragile lifeline to the north, subject to attack by pirates and foreign powers. The navy was frequently dispatched to escort the coal vessels, in convoys, down the English coast. Still, the coastal coal trade was seen not mainly as a vulnerability but as a national asset, and it came to enjoy what one historian called "an almost superstitious reverence" as the source of England's naval strength. There were even those in the 1600s who opposed trying to find inland coal supplies closer to London because it would have choked off the precious coastal trade.