Identifying First World War trenches
Following the recent discovery and excavation of practice trenches and tunnels in Wiltshire, Home Front Legacy 1914-18 have taken the initiative and produced this case study.
We will show you how to identify the earthworks associated with First World War trenches and give you an idea of what to look for when investigating sites in your local area.
When you think of the First World War, often the first thing to pop into your head is trenches and the fighting on the continent.
What you may not realise is that some of the first trenches of the First World War were constructed in Britain, following the outbreak of war. Soon after the declaration of war it was feared the German Army would invade immediately! As a precaution, trenches were dug on the South coast to protect the shores from the newly perceived invasion threat.
You never know, you might find a set of First World War trenches where you live!
Why were trenches used?
Trenches were adopted for protection when a stalemate developed in October 1914. Initially, the war had been very mobile, but following the ‘Race to the Sea’ neither the Entente forces or Central Powers were able to out-flank each other; with frontal attacks meeting heavy resistance and stalling.
Both sides ‘dug in’ to consolidate their gains, allow their soldiers to rest and to afford some protection from the murderous artillery and machine gun fire that dominated the battlefield. This stalemate was to be temporary; according to Notes for Infantry Officers on Trench Warfare, produced by the War Office in March 1916: “…trench fighting is only a phase of operations…”.
It is often stated that the machine gun caused most casualties between 1914 and 1918, however this is not true. Artillery was the most deadly weapon on the Western front; with more casualties being attributed to shrapnel, shell splinters and explosions than any other weapon employed on the front. Deep trenches were required to protect troops from incoming artillery barrages of both high explosive and shrapnel shells, while allowing them to hold the ground they had seized.
Over time the trench networks developed into elaborate defensive systems incorporating latrines, dugouts, machine gun positions, shelters and belts of barbed wire.
Why are there trenches in the UK?
There are many reasons why First World War trenches survive in the UK.
Practice trenches; used to train new recruits in the art of trench digging, and replica trench systems; for developing new tactics and rehearsing set piece battles, were commonly found on military training areas and land requisitioned by the military.
The land surrounding many of the newly established training camps, used by Kitcheners’ New Army and the Pal’s Battalions, was frequently used for the digging of practice trenches. These trenches were dug not only to train soldiers how to dig, but also to prepare them for their deployment. It was essential that all soldiers deployed were prepared for trench warfare and also had the necessary skills to live in, fight from, navigate and maintain trenches during their stint in the front line positions.
Trenches were also dug for defence. Numerous invasion scares throughout the war led to the construction of coastal and inland defensive trench systems; the most elaborate being the London Defence positions which stretched from Guildford to Dartford.
Trenches are very distinctive and some still survive as earthworks to this day. Although most of these trench systems were back-filled following training, or in the inter-war period, many can still be identified; if you know what to look for.
Surviving practice trench systems often reflect the diagrams found in War Office training manuals, such as Notes for Infantry Officers on Trench Warfare (1916). There are a number of features that make up a trench system; including different types of trenches and defensive measures, used to create ‘defence in depth’.
In a full scale trench system, as found on the front and outlined in War Office manuals, a system of three lines of defence was established. This consisted of the forward ‘main fire trench’; made up of a continuous line of fire trench and a ‘supervision trench’ 23 to 27 meters (25 to 30 yards) to the rear. This trench line housed the forward fighting line garrison during their rotation to the front where they would react to incoming attacks and hold the line.
Behind the forward position sat the second line of defence, or ‘support trench’ which consisted of a line of a single continuous line of fire trench, minus a supervision trench. Notes for Infantry Officers on Trench Warfare (1916) outlines that the support trench:
…should not be nearer than 50 yards [45 meters] behind it [the main fire trench], and the most favourable position is from 70 to 100 yards [64 to 91.5 meters] behind (War Office, 1916).
The support trench held the second garrison who would reinforce the main fire trench if it came under attack, or organise a counterattack if the main fire trench was captured by the enemy.
The final line of defence was the ‘reserve line’; sited a further 366 to 457 meters (400 to 500 yards) to the rear of the main fire trench; again, consisting of a line of fire trench.
Each of the three trench lines were connected by ‘communication trenches’ that zig-zagged between each successive trench line, allowing soldiers to move between trenches without being exposed to incoming fire.
All these features may be found within a First World War training area.
Fire trenches, as the name suggests, were used by the occupying soldiers to fire their weapons in the direction of the enemy. These frequently consist of evenly spaced forward projecting ‘fire bays’, with a protective ‘traverse’. This creates a very distinctive crenulated design, with the trench resembling the crenulations of a castle rampart. There were many different designs and types of fire trench but the crenulated type is by far the most commonly encountered.
Dimensions of these trenches vary significantly, with fire bays measuring from 3m (10ft approx) to 12m (40ft approx) in length and traverses measuring between 2.7m (9ft approx) 3.6m (12ft approx) in length. Fire bays are often around 2 meters wide but again dimensions vary significantly, even more so when the trench has been backfilled.
Traverses tend to be square in plan while some earlier trenches may feature a very long fire bay with rounded traverses (See Redmires Training Area below).
Communication trenches can often be found behind a line of fire trench leading to further positions to the rear. In contrast with fire trenches, communication trenches tend not to be crenulated to aid the movement of soldiers and stretchers evacuating wounded.
This type of trench is either formed of a zig-zagging or curved trench between 0.9 and 1.5 meters (3 and 5 feet) in width.
Soldiers also had to be able to construct saps (listening posts), shelters, latrines (toilets), aid posts and dugouts (deep shelters).
Saps were small trenches that extended forward from the main fire trench, towards the opposing enemy trenches. A sap would be manned around the clock to provide an early warning of an incoming attack and could also be used to gather intelligence and send patrols out into no-man’s land. Saps will be found extending from the forward fire trench by means of a communication trench; this communication trench terminates with a smaller trench; again a number of different types can be encountered (See diagram).
Shelters would be needed within the actual frontline trenches to protect the occupants from incoming shrapnel and shell splinters during bombardments. Shelters are often found extending to the flanks of the communication trenches that join the supervision trench and main fire trench. Smaller shelters, known as cubby holes, were also constructed within the face of the supervision trench. Cubby holes were used by soldiers to rest and take cover from incoming fire.
Soldiers would still need to be able to go to the toilet and were properly training in constructing latrines. Latrines ensured diseases spread through human waste were kept to a minimum and were an integral part of a trench system. Latrines are also encountered in practice and replica trench systems. These are often found on projecting to the rear of the supervision trench.
The first step in identifying practice trenches is to research First World War training areas and coastal defences in your local area. This can include an online search, reading local history books and visiting your local archive service.
Even old newspaper articles can prove useful. Our Project Archaeologist recently found references in local newspapers from the period highlighting an area where the Royal Engineers practised digging trenches. This will form the basis of further research and eventual fieldwork to record any remains with the Home Front Legacy recording app.
You can find out how to start your research in our Desk Research section.
Aerial Photographs & LiDAR
Once you have identified a training area you can start to investigate the landscape from above. Online resources, like Google Earth and Bing maps provide you with high resolution aerial photographs covering most of the country. Using these resources is a great way of finding potential earthworks.
The House Prices website features a simple to use online app that allows you to view LiDAR images. Though coverage of the UK is not complete it is still a very useful app for finding low lying earthworks. You can search for your area by typing the grid reference into the menu bar.
Recording your findings and field work
You can find out more information about conducting your own field work in our online Site Recording Guide. Here you will find all the information you need to conduct your own field recording and recording your site with the Home Front Legacy recording app.
Before visiting a site always ensure you have landowner consent to access the land and never attempt to excavate any remaining earthworks. Doing so will damage the underlying archaeology and also endanger the long term conservation of surviving earthworks.
Also consult our Site Safety section before heading out.
Second World War trenches
Many First World War practice areas were re-used during the Second World War. As a result some of the earthworks you identify may date from the Second World War. If you are unsure then drop our Project Archaeologist an email at firstname.lastname@example.org
Redmires Training Area
The Redmires Training Area is a Scheduled Ancient Monument. You can read the report here
Penally Practice Trenches
Rothbury Practice Trenches
The Rothbury Practice Trenches are a protected Scheduled Ancient Monument. You can read the report here
The First World War practice trenches at Oswestry Hillfort are protected as part of the site’s Scheduled Ancient Monument status. View the report here
The Home Front in Britain 1914-1918 book that accompanies our project features more information about First World War trenches in the UK. Order your copy from Oxbox books now.
Find out more about the First World War trenches that protected London WW1 on the Anti-invasion Defences and Home Defence website.
The General Staff, 2015. Notes for Infantry Officers on Trench Warfare, March 1916. Edition. Naval & Military Press.
2014. BRITISH TRENCH WARFARE 1917-1918. A Reference Manual. Edition. Naval and Military Press.