Question about convoys' navigation at night

[ArnoldR]

Hello,

In the game, the ships have no lights at all during the night. In reality, how was it possible for ships sailing in convoys to not collide each other without any position lights at all? Is there anyone who read something about night navigation of the WWII convoys? How was it possible in practice? What were the tactics?

Thank you for any answer.

:Kaleun_Salute:

[Anvar1061]

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https://www.subsim.com/radioroom/showpost.php?p=1391888&postcount=3

[John Pancoast]

Hello,

In the game, the ships have no lights at all during the night. In reality, how was it possible for ships sailing in convoys to not collide each other without any position lights at all? Is there anyone who read something about night navigation of the WWII convoys? How was it possible in practice? What were the tactics?

Thank you for any answer.

:Kaleun_Salute:

There are many books that touch the subject, some exclusively. Just do a google search and see which you want.

I've never sailed the oceans but I would think since the captains were given navigation info. just by sticking to it they would avoid each other.
I.e., stay at heading xxx until further orders.

They weren't supposed to be sailing any which way they wanted to.

[CaptBones]

Having spent most of a 30-year Navy career at sea, I've steamed in formation without lights quite a few times; in company with aircraft carriers, cruisers and even battleships. Even in the deadest darkness of night, at distances of 500-1000 and usually out to several miles, the shape/shadow of a ship is very noticeable. An experienced seaman can make out a vessel and with fairly good accuracy, determine its AOB/heading and even the approximate speed. Most importantly, you can judge the relative movement of even a darkened vessel at several miles ("CBDR" is that red flag that you want to avoid..."constant bearing, decreasing range").

To be sure, merchant ship Captains (Masters) as well as their First and Second officers are generally more than just a little bit experienced. Most of those who sailed in convoys in WWII were genuine "Old Salts" and would have little trouble keeping station in all but the worst weather conditions. In those conditions, the convoys would be dispersed precisely because station keeping would be impossible, even with navigation lights and those lights turned the ships into big, fat targets. But then, dispersing a convoy was also asking for trouble; trying to get out of that collection of ships, all of which were also trying to get away, was itself an invitation to potential collisions all around. There were also collisions due to other factors; propulsion/steering breakdowns and the like, or just inattention or confusion by bridge watch personnel.

The dimmed white stern light was adequate for assisting ships to maintain station in convoy under most circumstances...follow the leader, but no too close. The lead ship in each column had to keep station on the other column leaders, 90 degrees to port and/or starboard and at the desired distance. Even at 500-1000 yards at night, determining distance with a stadimeter is usually not that difficult. However, contrary to the idea that the dimmed stern lights were helpful in foggy conditions, in anything more than just a very light fog, a dimmed white light in fog is almost useless.

[John Pancoast]

Great info. CB, thanks !

[ArnoldR]

Thank you Sir for the long reply, I enjoy it quite a lot when experienced guys explain me what they know!

Having spent most of a 30-year Navy career at sea, I've steamed in formation without lights quite a few times; in company with aircraft carriers, cruisers and even battleships. Even in the deadest darkness of night, at distances of 500-1000 and usually out to several miles, the shape/shadow of a ship is very noticeable.

But when the sky is fully covered with clouds?... you can see nothing at night in the middle of the sea... am I correct?

The dimmed white stern light was adequate for assisting ships to maintain station in convoy under most circumstances...follow the leader, but no too close. The lead ship in each column had to keep station on the other column leaders, 90 degrees to port and/or starboard and at the desired distance. Even at 500-1000 yards at night, determining distance with a stadimeter is usually not that difficult. However, contrary to the idea that the dimmed stern lights were helpful in foggy conditions, in anything more than just a very light fog, a dimmed white light in fog is almost useless.

So, there was at least a position light for each ship. That was the info I was searching for. Thank you very much. :up:

[CaptBones]

...but, to answer the question...no, not really.

Mostly cloudy or overcast skies generally don't make much difference. Yes, starlight and moonlight are filtered or blocked almost completely. However, there is still a distinct difference along the line of the horizon (provided you have decent "night vision" to begin with). In fact, clouds beyond the horizon will often help you to see the shape of a vessel that is on or just beyond the horizon (hull down). Unless you're looking at/for a small silhouette or shadow (like a surfaced U-Boat) at close range, you can readily make out the shape/shadow of a vessel at a good distance.

The hard part is seeing those small shapes at close range. When you're looking "down", those tend to merge with the darkness of the water. But, they also tend to produce waves/foam along their waterlines, provided they are moving at more than a crawl. That will give them away...unless the seas are a little rough and wave action is producing whitecaps and some foam, which it almost always is. It is often the case that lookouts in small vessels can spot things on the surface at night more easily than lookouts in large vessels. They are down closer to the surface and the line of the horizon is closer, paradoxically meaning they can see shapes and shadows farther away. One of the "tricks of the trade" for night operation in blackout conditions is to put extra lookouts down on the lowest weather deck...young kids with good night vision come in very handy.

Fog is the real problem at night...during the day as well, of course. It eliminates the horizon and shrouds even the largest ships (not to mention rocks, reefs, buoys, lighthouses, and everything else out there). In foggy conditions, sound becomes much more important than sight for "seeing" things. Sound carries over long distances in fog and can reveal the presence of a vessel miles away. That's when young kids with good hearing come in very handy.

[ArnoldR]

...but, to answer the question...no, not really.

Mostly cloudy or overcast skies generally don't make much difference. Yes, starlight and moonlight are filtered or blocked almost completely. However, there is still a distinct difference along the line of the horizon (provided you have decent "night vision" to begin with). In fact, clouds beyond the horizon will often help you to see the shape of a vessel that is on or just beyond the horizon (hull down). Unless you're looking at/for a small silhouette or shadow (like a surfaced U-Boat) at close range, you can readily make out the shape/shadow of a vessel at a good distance.

The hard part is seeing those small shapes at close range. When you're looking "down", those tend to merge with the darkness of the water. But, they also tend to produce waves/foam along their waterlines, provided they are moving at more than a crawl. That will give them away...unless the seas are a little rough and wave action is producing whitecaps and some foam, which it almost always is. It is often the case that lookouts in small vessels can spot things on the surface at night more easily than lookouts in large vessels. They are down closer to the surface and the line of the horizon is closer, paradoxically meaning they can see shapes and shadows farther away. One of the "tricks of the trade" for night operation in blackout conditions is to put extra lookouts down on the lowest weather deck...young kids with good night vision come in very handy.

Fog is the real problem at night...during the day as well, of course. It eliminates the horizon and shrouds even the largest ships (not to mention rocks, reefs, buoys, lighthouses, and everything else out there). In foggy conditions, sound becomes much more important than sight for "seeing" things. Sound carries over long distances in fog and can reveal the presence of a vessel miles away. That's when young kids with good hearing come in very handy.

Thank you very much for this detailed reply again! :up:

I'm not a sailor, and your explanation is very helpful to me who has never seen a "real" night. That might be very strange to be able to spot objects in a cloudy night, I guess...