Analysis[ edit ] The success of convoys as an anti-submarine tactic during the world wars can be ascribed to several reasons related to U-boat capabilities, the size of the ocean and convoy escorts. Submerged speed and endurance was limited and not suited for overhauling many ships.
Even a surfaced U-boat could take several hours to gain an attack position. Torpedo capacity was also restricted to around fourteen Type VII or 24 Type IX , thus limiting the number of attacks that could be made, particularly when multiple firings were necessary for a single target. There was a real problem for the U-boats and their adversaries in finding each other; with a tiny proportion of the ocean in sight, without intelligence or radar, warships and even aircraft would be fortunate in coming across a submarine.
Conversely, a U-boat's radius of vision was even smaller and had to be supplemented by regular long-range reconnaissance flights. For both major allied navies, it had been difficult to grasp that, however large a convoy, its "footprint" the area within which it could be spotted was far smaller than if the individual ships had traveled independently. In other words, a submarine had less chance of finding a single convoy than if it were scattered as single ships. Moreover, once an attack had been made, the submarine would need to regain an attack position on the convoy.
If, however, an attack were thwarted by escorts, even if the submarine had escaped damage, it would have to remain submerged for its own safety and might only recover its position after many hours' hard work. U-boats patrolling areas with constant and predictable flows of sea traffic, such as the United States Atlantic coast in early , could dismiss a missed opportunity in the certain knowledge that another would soon present itself.
The destruction of submarines required their discovery, an improbable occurrence on aggressive patrols, by chance alone. Convoys, however, presented irresistible targets and could not be ignored. For this reason, the U-boats presented themselves as targets to the escorts with increasing possibility of destruction. In this way, the Ubootwaffe suffered severe losses, for little gain, when pressing pack attacks on well-defended convoys.
In the present day, convoys are used as a tactic by navies to deter pirates off the coast of Somalia from capturing unarmed civilian freighters who would otherwise pose easy targets if they sailed alone.
Road convoys[ edit ] Humanitarian aid convoys[ edit ] The word "convoy" is also associated with groups of road vehicles being driven, mostly by volunteers, to deliver humanitarian aid , supplies, and—a stated objective in some cases—"solidarity".
They also travel to countries where standards of care in institutions such as orphanages are considered low by Western European standards, such as Romania ; and where other disasters have led to problems, such as around the Chernobyl disaster in Belarus and Ukraine. The convoys are made possible partly by the relatively small geographic distances between the stable and affluent countries of Western Europe, and the areas of need in Eastern Europe and, in a few cases, North Africa and even Iraq.
They are often justified because although less directly cost-effective than mass freight transport, they emphasise the support of large numbers of small groups, and are quite distinct from multinational organisations such as United Nations humanitarian efforts. Most truckers had difficult schedules to keep and as a result had to maintain a speed above the posted speed limit to reach their destinations on time. Convoys were started so that multiple trucks could run together at a high speed with the rationale being that if they passed a speed trap the police would only be able to pull over one of the trucks in the convoy.
When driving on a highway, convoys are also useful to conserve fuel by drafting. The film Convoy , inspired by a song of the same name , explores the camaraderie between truck drivers , where the culture of the CB radio encourages truck drivers to travel in convoys. They have to be treated like a single vehicle. If the first vehicle has passed an intersection, all others may do so without interruption.
If other road users overtake the convoy, they aren't allowed to split into the queue. Clear and uniform marking has been required in court decisions for these rights to apply. Operating such convoy usually needs special permission, but there are exemptions for emergency and catastrophe intervention. Common practice is, to operate with the same style of marking as NATO convoys: Today, catastrophes like large-scale flooding might bring a high number of flagged convoys to the roads.
Large-scale evacuations for the disarming of World War II bombs are another common reason for non-governmental organization NGO unit movements under convoy rights. Storm convoys[ edit ] In Norway, "convoy driving" Norwegian: Convoy driving is initiated when the strong wind quickly fills the road with snow behind snowplows, particularly on mountain passes.
During the winter of there was convoy driving for almost hours at Saltfjellet .