Understanding Trench Maps

[andigger]

After following a few threads about trench maps and locations I have often wondered what a trench map tells you. I have attached a couple of maps from previous threads to this thread in hopes that Dave and others might be able to explain what they are showing and what I might be missing. Thanks, Andy

1. Would barricades be common, even in 1914-15?

2. What are these?

3. Are these shallow trenches, a 'regular' advanced firing line?

4. Why would these trenches be identified as'used'? Why also are two German trenches parallel to one another?

5. What are these?

6. Why would the German and British trenches come together like this?

7. What is this?

I am sure there are many other questions, but I really wanted to start a discussion/learning session for those of us who knew less about these maps.

Thanks, Andy

[andigger]

Here is another map from a previous thread....

1 and 2. What are these?

3. Why are there no supporting trenches in this sector?

[Robert Dunlop]

I can quickly answer a few of the questions:

Barricades is a generic term for some form of obstacle (comes from the word for weirs in a river). The BEF used them in situations, such as villages, where they sought to block German troops, in combination with defensive positions in neighbouring houses. As such, barricades were used from 1914 on.

British and German trenches would 'come together' if one or other side had captured part of an existing trench system. Trench blocks would then be created - obstacles to movement down the trench, coupled with covering defensive position/s.

The British would often leave supporting trenches off their maps for security reasons.

Off to work now. More later if no additional replies.

Robert

[Annette Burgoyne]

Hi Andy

I do not know this area very well but I am sure it shows a captured area that why half of some of the trenchs are held by British and other half by Germans as Robert as pointed out.

(3) Dotted line are disused trenches.

(4) One would have been the oringinal front line with its support trench behind it.

(5) I think these are strong points in the line ? also same for number (2) in second map. Also with second the other could be assembly trenches.

Annette

[CROONAERT]

Andy.

In answer to your questions....

1. Barricades were most common in 1914-15 and also 1918 (which is the date of the map you illustrate (57D NE, July 1918)

2. A "camp area" - an area of various hutments and shelters.

3. Disused/old trenches

4. The "used" is actually referring to the road. Why shouldn't they be parallel?

5. Dugouts

6. Already explained by Robert

7. "Holes" (variety of meanings ,such as "foxholes", etc).

On your (my!) second map...

1. Pass? No idea whatsoever (accomodation trenches?)

2. Loops in the trench system

3. There are! On this early 1916 (March) there are no Allied trenches shown. The German frontline is shown as a thicker red line, but the support trenches are behind it.

Dave.

[andigger]

Thanks Robert and Dave..... Just a couple of follow ups.

4. It appears that these two parallel trenches were never front line trenches, so I am not clear what the benefit would be to either side to have two trench systems so close? The benefit redundancy would seem to be neglegible.

7.If these were fox holes what would thier purpse be so far behind the front line? Could these be artillery spots? Are artillery marked on trench maps?

2 (Second map) What are 'loops' in the trench system? A place for running laps?

Thanks for the insight though everyone, this is very helpful! Andy

[CROONAERT]

Andy.

4. You have to bear in mind that this is a 1918 trenchmap of an area that was also heavily entrenched in 1916. Some of these trenches would be old communication trenches that have had to be re-used. There is also the possibility of "one way" trenches where troops can only travel down it in the one direction and have to return via the other trench.

7. Artillery is sometimes marked on trenchmaps, but not by these symbols. They're not necessarily foxholes ,but they do represent "earthworks" of some sort. They could even be a line of "shellholes organised for fire" as a defensive position. They're not all that far behind the frontline, by the way, some being only 200 to 300 meters behind it.

2.(second map). A loop is,well - a loop! it might be where a trench has been dug all round something for some reason, or simply so it can be used as a passing place inside the trench. A variety of reasons for a loop.

Dave.

[CROONAERT]

Andy.

You might find this of use. It doesn't show half the symbols actually used but it's a good starting point...

Dave.

[Robert Dunlop]

The other possibility for 4 is a 'switch line'. This would be a line of trenches created at an angle to the front line, running between the first line and/or second and/or subsequent lines of trenches. The switch line would serve as a new 'front line' in the event that the enemy broke through the first line of trench defences.

Isolated lines of fox holes might indicate trench mortar positions. Sometimes, all that could be seen was the opening through which the trench mortar fired. Access to the pit was by tunnel. However, the opening had a very characteristic appearance on aerial photographs and would be likely to be registered as a TM position on the map.

As for 'loops', one of the major problems during an attack was the flow of reinforcements down a support trench being severely slowed by the stretcher bearers and walking wounded coming the other way. Parallel trenches, one in-coming and one out-going, was one solution. Loops provide the same effect for short distances. Another reason for these loops is that they represent all-round defensive posts. Trench blocks could be placed at either end of the 'loop' and you had several mutually supporting defensive posts with 360 degree fields of fire.

Robert

[Robert Dunlop]

Artillery posts were usually not so far forward. There were occasions when field guns were bought into the front line to provide direct fire support for attacking infantry. This happened in some of the battles in 1915. The emergence of tanks saw both sides using field guns as anti-tank guns. In the German Spring offensive of 1918, fear of tanks saw British RFA brigades detach single guns into the front line for duty as anti-tank guns. Most were captured or destroyed.

I was just reading yesterday of an encounter between British and German soldiers in the last 100 Days. The trenches were very close together, somewhere on the old Somme battlefield. Two British soldiers were walking past when a German officer stood up and attempted to talk to them. He was shot down. Then a teenager did the same thing. He was allowed to cross the short distance and surrender.

Some of the most difficult fighting occurred when two trench lines 'joined'. It happened quite a lot in the Battle of the Somme. Both sides would keep attacking each other over trench blocks, mainly using grenades but sometimes Lewis guns or a machine gun might to be used. Nasty.

Robert

[CROONAERT]

Andy.

You might find this of use. It doesn't show half the symbols actually used but it's a good starting point...

Dave.

Similar to my last post, but this shows an extra couple of conventional signs...

dave.

[CROONAERT]

A question of my own now.

Has anyone any idea why Oppy Trench (running north to south immediately west of Oppy Wood) would be depicted as this on this Feb. 1916 trenchmap? (It is also depicted the same on a 1917 map, but not on a 1918 map). Surely it can't be "looped" for such a long distance (this particular trench runs for approx. 9miles using this symbol!!!)

What does it mean, and why?

Thanks,

Dave.

[andigger]

Dave, Thanks for putting a lot of this information on your web site.

http://pathsofglory.co.uk/contents.htm

Andy

[CROONAERT]

Dave,  Thanks for putting a lot of this information on your web site.

http://pathsofglory.co.uk/contents.htm

Andy

<{POST_SNAPBACK}>

Thanks for the "plug", Andy!!!

To see the map extracts on this site click HERE

Dave.

[CROONAERT]

To see the map extracts on this site click HERE

... Or for general trenchmap information click HERE.

Dave.

[CROONAERT]

After following a few threads about trench maps and locations I have often wondered what a trench map tells you.  I have attached a couple of maps from previous threads to this thread in hopes that Dave and others might be able to explain what they are showing and what I might be missing.  Thanks, Andy

1. Would barricades be common, even in 1914-15?

2. What are these?

3. Are these shallow trenches, a 'regular' advanced firing line?

4. Why would these trenches be identified as'used'?  Why also are two German trenches parallel to one another?

5. What are these?

6.  Why would the German and British trenches come together like this?

7. What is this?

I am sure there are many other questions, but I really wanted to start a discussion/learning session for those of us who knew less about these maps. 

Thanks, Andy

<{POST_SNAPBACK}>

As requested, Andy, here's the image from your opening post on this thread...

Dave.

[CROONAERT]

A question of my own now.

Has anyone any idea why Oppy Trench (running north to south immediately west of Oppy Wood) would be depicted as this on this Feb. 1916 trenchmap? (It is also depicted the same on a 1917 map, but not on a 1918 map). Surely it can't be "looped" for such a long distance (this particular trench runs for approx. 9miles using this symbol!!!)

What does it mean, and why?

Thanks,

Dave.

<{POST_SNAPBACK}>

And just in case I can now get an answer to my own question , here's the image from my particular post (above).

Dave.

[andigger]

Dave - Thanks for reposting the map... I had to go back the thread myself (thanks to you and Kate I was able to get to the archive.) Although I guess I could have looked on your great site, the ultimate trench map resource www.pathsofglory.co.uk!

In this map there are the boxed parallel lines which we couldn't figure out what they were. I am currently reading Ian Passingham's book Pillars of Fire and similar 'trenches' show up on his railways map specifically near Swiss Cottage, due north of Peselhoek in June 1917. My thought (and still only a guess) is that these might be off loading points, where trains.. or light rail cars were on loaded or off loaded near the front line, much like a railyard would be.

Would this make sense?

Andy

[CROONAERT]

In this map there are the boxed parallel lines which we couldn't figure out what they were.  I am currently reading Ian Passingham's book Pillars of Fire and similar 'trenches' show up on his railways map specifically near Swiss Cottage, due north of Peselhoek in June 1917.  My thought (and still only a guess) is that these might be off loading points, where trains.. or light rail cars were on loaded or off loaded near the front line, much like a railyard would be.

  Would this make sense?

<{POST_SNAPBACK}>

Andy.

I don't think so.

Those on the map on page 14 of Pillars of Fire actually are rail-yards, not trenches, and are situated some 4 to 5 miles behind the front-line. The ones on the trenchmap you illustrate are trenches arranged thus for some reason unknown to me (unless they simply lead to dugouts), and only 800 yards or so behind the frontline. I suppose they could be for a trench railway, but these are usually depicted by their own conventional sign.

The map you illustrate is a 1:20,000 scale map which might miss some detail, but the 1:10,000 scale equivalent doesn't show a rail symbol either, and ,indeed, proves them as they are...trenches.

Dave.

[CROONAERT]

the 1:10,000 scale equivalent doesn't show a rail symbol either, and ,indeed, proves them as they are...trenches.

<{POST_SNAPBACK}>

...and here's a scan of the same "odd" trenches a couple of months later from a 1:10,000 map. As you can see, they're not straight enough to have contained rails...

Dave. (and I bet this scan only makes more questions, rather than answers them! - the "comb-like" firing points, the single trench access, the singular long trench - I'd like to know about these too! )

[egbert]

I strongly believe they are billeting-trenches with lots of dugouts; I have seen similar structures near Achiet for German billeting trenches leading to deep dugouts

[jhill]

I would hazard a guess that the "comb-like" objects are dumps. The British practise seemed to be that battalion dumps were at or near the support line while Brigade dumps were a bit further back. They may sometimes have been constructed looking something like a comb.

Of course, I would like to hear from someone who knows for sure.

[andigger]

and I bet this scan only makes more questions

<{POST_SNAPBACK}>

Yeah! Like....whats the triangle?????

Andy

[CROONAERT]

Yeah!  Like....whats the triangle?????

Andy

<{POST_SNAPBACK}>

It's very similar to the symbol for a supply dump.

Either that, or they're simply trenches linking the two others that have formed what seems to be a triangle. Hard to tell really - it's no clearer on the original.

( Personally, though, I don't think it's the SD symbol because it's too small and one of the sides isn't straight).

Dave.

[Compo]

Those close parallel trenches, just a wild guess but could the answer be horses?

I was thinking, a safe place to keep cavalry,transport or artillery horses within enemy artillery range but therefore nearer to the action ready for rapid deployment.

The comblike structure reminds me of a row of horse stalls and the "castellations" on the other trenches might have been a means to reduce the chances of the horses bolting in a panic, harder to make all those turns.

Of course I have never heard of trenches to protect horses being dug, but is it such a leap if the same was being done for the men? If horses were falling as casualties in numbers to create a shortage perhaps it became worth the effort.

Done speculating, Bill