From 3D model to public outreach

On March 16, 2019, the new Battery Aachen presentation at the Atlantikwall open-air museum in Raversyde, Belgium, opened for the public.  Earlier posts in this blog described how we made the 3D virtual reconstruction for 1915 and 1917 of this unique German WW1 site.  In this blog post, we describe how the 3D models of these virtual reconstructions were re-used in this new site presentation.

Objects and models inside the former house of the lighthouse operator tell the story of Battery Aachen (photo: Daniel Pletinckx)

In the former house of the lighthouse operator, a small museum presentation has been created with outstanding objects.  To show how the site appeared to French and British ships potentially attacking this coastal defence unit, a 3D model has been printed by Materialise derived from the 3D virtual reconstruction model.

Exhibition of objects related to Battery Aachen (photo: Atlantikwall Raversyde)

3D printed model of Battery Aachen in 1917 (photo: Daniel Pletinckx)

The 3D printed model has been realised through a combination of printing techniques (photo: Daniel Pletinckx)

A new outdoor model of Battery Aachen has been cast in concrete to help visitors understand the structure of the site, at the start of the new walking trail that shows the WW1 remains.

A guide is explaining the site with the new concrete site model (photo: Daniel Pletinckx)

New outdoor model of Battery Aachen in concrete (photo: Daniel Pletinckx)

The concrete model has been cast in a specifically designed and 3D printed mould (photo: Daniel Pletinckx)

One of the guns of Battery Aachen has been cast in concrete on scale 1:1, based upon the 3D model of the gun in the virtual reconstruction. This mockup gun allows experiencing the size and emplacement of a gun in its bunker.

Concrete scale 1:1 gun in its original position (photo: Daniel Pletinckx)

The individual visitor can use a tablet to learn about the site on selected spots.  On each of these spots, the visitor can experience the site in 1917 and 1915 through virtual panoramas derived from the 3D reconstruction, complemented with text and a number of images and schematic animations.

Mobile guide for visitors showing the 3D reconstruction of Battery Aachen in 1915 and 1917 through virtual panoramas (photo: Atlantikwall Raversyde)

The most important use of the 3D reconstruction is the virtual tour for guided groups.  Up to 30 people can enter a bunker on the site to experience an interactive 3D visualisation of the site, presented by a guide.

Guide using the interactive 3D virtual tour to explain the history of Battery Aachen (photo: Daniel Pletinckx)

The original 3D virtual reconstruction, made to produce rendered images, has been transformed into a real-time interactive 3D environment, in which a path system and several animations have been added.

Start of the virtual tour with the guiding path as a white line (image: Visual Dimension)

The path system gives the guide an easy way to walk around in the virtual site of Battery Aachen in 1917 while talking and interacting with the visitors.  The guide uses a games controller for navigation through the 3D model.  We have implemented both the normal two-handed games approach but also a one-handed approach where the guide can use the free hand to gesture or indicate objects (for example with a laser pointer).  The buttons on the controller implement specific functionalities: quit/resume the path, show the site from an elevated point of view, go quickly to a small number of predefined key locations or play specific animations at certain areas.

View on one of the guns and the entrances to its ammunition bunkers (image: Visual Dimension)

For example, when coming at one of the guns, the guide can enter the ammunition bunkers underneath, showing how grenades and charges were prepared for firing.  Although these bunkers have been restored, they remain inaccessible for the visitors, while the handling of ammunition needs to be virtual anyway.  Also, the operation of the unique ammunition elevator has been reconstructed virtually.

Interactive view on the right ammunition bunker (image: Visual Dimension)

Animation showing the operation of the ammunition elevator (image: Visual Dimension)

After the virtual presentation, the group visits the site, walking the same path as in the virtual tour, while the guide can relate specific locations to the 3D presentation.

Virtual view on the Barbara Brunnen in 1917 (image: Visual Dimension)

Real view on the restored Barbara Brunnen today (photo: Daniel Pletinckx)

 

 

A guided tour in Battery Aachen – part 2

This second part of our tour of Battery Aachen shows us to some other distinct features on the current site that can be linked to Battery Aachen in 1915 and 1917.

When you enter the current open air museum, you see two buildings that were already present in 1914. The larger building was the home of the lighthouse keeper.  Two lighthouses in the dunes of Raversyde were guiding ships, arriving in the harbour of Ostend.  From a ship, the smaller lighthouse on the top of the dunes had to align with the larger lighthouse a bit further inland.

The entrance building in December 2013

Small building at the entrance of the open air museum in December 2013

The lighthouses were considered to be an easy target for ships attacking from the sea, so both were taken down in the winter of 2015, when Battery Aachen was being finalised.

Taking down the large lighthouse begin 1915

The broken large lighthouse in front of the house of the lighthouse keeper (1915)

The entrance of Battery was only 50 m south of the current entrance, the site was fenced off by multiple lines of barbed wire, as can be seen in the virtual reconstruction below.

Virtual reconstruction of the area in 1915 and 1917

Battery Aachen was built on the Royal Estate at Raversyde, established by king Leopold II in 1903. The site contained several wooden houses that were taken down or left unused.  One building, that was damaged by aerial attacks on the site but survived the war, is the Norwegian House.

The Norwegian House of the Royal Estate (1903)

The Norwegian House around 1920

Today, nothing is left of the building, but the virtual reconstruction shows the damage to the house due to the air shocks of explosions nearby.

The damaged Norwegian House of the Royal Estate (1917)

To allow defending the site of Battery Aachen, it was not only surrounded by barbed wire but had also an extensive system of trenches.  Some of these trenches are still visible today.

Defensive trenches on the west side of Battery Aachen

The photo below shows soldiers training on countering a beach landing of Allied troops.  Note the freshly planted beachgrass and the greensward in front of the trench.

Training for an Allied beach landing at Battery Aachen (1915)

This beach side trenches were connected to a network of trenches surrounding the west side observation bunker.

Virtual reconstruction of the defensive trenches at the west side of Battery Aachen (1915-1917)

The core of Battery Aachen were the platforms with four 15 cm SKL40 guns.  All four concrete platforms are preserved and two of them are accessible.

The gun platform on the east side of Battery Aachen

These gun platforms were quite open in their original conception in 1915 but got extra protective structures after the first attacks on the site.  The guns became nearly invisible in the dune landscape.

Gun platform of the east side of Battery Aachen (1915)

Same gun platform at the end of the war in 1918

Virtual reconstruction of the same gun platform in 1915

Virtual reconstruction of the same gun platform in 1917

A guided tour in Battery Aachen – part 1

Walking around at the Atlantikwall site of Raversyde, our virtual reconstructions link the past to the present. Let’s have a quick tour around this German coastal defense unit in 1915 and 1917.

At the entrance, two British sea mines, used as planters, were welcoming the visitor.

Former entrance of Battery Aachen at_Raversyde

Former entrance of Battery Aachen in the winter of 1916 or 1917

Virtual reconstruction of the entrance in summer 1917

Virtual reconstruction of the entrance in summer 1915

There was a path, connecting the two observation bunkers, that passed in front of the cannon platforms, but also gave access to the stairs of the former royal villa that gave way to the first line defence positions on the beach.

Current situation at battery Aachen with mainly WW II remains

The connecting pathway on the seaside in 1918

Virtual reconstruction of the connecting pathway in 1917

Virtual reconstruction of the connecting pathway in 1915

The soldiers were living in barracks that were integrated in the dunes, the planted layer of soil on the roof was acting as camouflage and protection against bombardments.  The barracks were reinforced after the British bombardment in October 1915.

Construction of the barracks in early 1915

Reinforced barracks in 1917

Virtual reconstruction of the barracks in 1915

Virtual reconstruction of the reinforced barracks in 1917

Battery Aachen contained four cannon platforms, that were also reinforced after the 1915 bombardments.  The cannons were put out of order by an inside explosion when the German troops withdrew at the end of the war.

Cannon platform today

Cannons platforms in 1918, the roof of the cannons is blown away by the explosion

Virtual reconstruction of the cannon platforms in 1917

Virtual reconstruction of the cannon platforms in 1915

Virtual reconstruction of Battery Aachen

Typically, virtual 3D reconstruction is used for archaeological sites or ruined monuments, where little is left to imagine what has been at a certain site in the past.  In the open air museum Raversyde Atlantikwall however, the situation is different.  A battery unit of the German coastal defense, called Aachen, was not only preserved after the first World War but was also reused by the German army in the second World War, and preserved after that war too, making it impossible to restore the WW I remains without touching the WW II remains.  So virtual reconstruction has a triple goal here: visualising the extant remains in their WW I state, showing the many WW I elements that are not preserved today and showing the evolution that the battery went through during the war.

Our virtual 3D reconstruction is based upon five types of sources: aerial photography, photography on the terrain, photographs of similar batteries, written sources and the extant remains.  Let’s start with aerial photography.  Airplanes were brand new in 1914, the first successful flight only happened in 1904.  By 1912, planes were build for military use, in fact, most of the early production of airplanes was destined at military goals.  One of them was aerial photography, so by 1915 we have reconnaissance flights that depict Battery Aachen regularly.  During the war, the battery was photographed regularly from the air, so we can observe the changes that happened over the period 1915-1918, only limited by the quality and detail of the different aerial photographs.

Aerial photographs of Battery Aachen during 1915

Aerial photographs of Battery Aachen in 1918

Current state of Battery Aachen

A second source are the terrestrial photographs taken on the terrain by soldiers and the military PR units.  These photographs show a wide range of subjects and areas and provide a lot of essential detail for the virtual reconstruction, as long as the photographed area can be identified.  Also photographs taken by Belgian soldiers in 1918, when the abandoned battery was taken, were very useful.

One cannon platform at its installation in 1915 – the railing was recuperated from the royal villa

When interpreting the aerial and terrestrial photographs, it is very useful to have additional photographs of the housing and and equipment of similar batteries.  For example, as we did not have plans of the cannons, we used additional photographs of the same cannons in other batteries.

A major element of the virtual reconstruction is functional analysis: we try to understand how the battery functioned and which role each of the identified elements had.  In this analysis, additional written sources are very useful.  We used for example spy reports that described the battery and its operations but also plans of the bomb elevator that brought projectiles from the storage bunker onto the cannon platform.

All bunker and cannon platform remains were measured outside and inside and analysed to distinguish between the different phases during the first WW and the later additions of the second WW.

Based on the plan and terrain model of today, we identified all man made structures on the aerial orthophotomap and estimated sizes and integration in the landscape.  This is far from trivial as the quality of the aerial photography was substantially lower than today.

Identification of build structures on the aerial orthophotomap (image: Visual Dimension bvba)

Based on all these sources, we created a virtual reconstruction for the newly build battery Aachen around May 1915 and for 1917, showing the changes and reinforcements made after the bombardments by the British Navy in October 1915.  Many dimensions and materials were derived (or sometimes guessed) from the photographic material and the length of shadows on the aerial photos.

An overview of Battery Aachen in 1915 (image: Visual Dimension bvba)

In this way, many elements in the current archaeological park can be linked to old photographs and visualised in 1915 and 1917 by the virtual reconstructions.

Current state of a cannon platform at the Raversyde open air museum

The same cannon platform in operation around 1917

The virtual reconstruction of the same cannon platform in 1917 (image: Visual Dimension bvba)

The virtual reconstruction of the same cannon platform in 1915 (image: Visual Dimension bvba)

Battery Aachen – 1915

Our story starts in the first months of the first World War, then called the Great War.  After conquering most of Belgium in October 1914, the German army consolidated its positions. Shortly after that, the construction started of a string of coastal defense units.

Construction of the artillery positions of Battery Aachen in January 1915

Construction of the artillery positions of Battery Aachen in January 1915

Installation of one of the artillery pieces in early 1915

The construction of Battery Aachen started in January 1915, at Raversyde, a village on the outskirts of Ostend, Belgium. Battery Aachen was the first of a long chain of defensive units along the Belgian coast: west of Battery Aachen was the front line, on the east side was Battery Antwerp.  The unit contained two observation bunkers, four artillery positions, housing for the staff, ammunition depots. Battery Aachen was build on the Royal domain and the royal villa was even burned down and replaced by an artillery position.

Overview of Battery Aachen as build in 1915 (image: Visual Dimension bvba)

The artillery (15 cm SK L/40) was positioned in open concrete structures, on top of a double storage room that was partially underground.  A double rail track allowed to bring ammunition from the central ammunition bunker to each of the artillery positions.

The artillery of Battery Aachen consisted of four 15 cm guns (image: Visual Dimension bvba)

The new Battery Aachen in spring 1915

A small detail in the image below: the railings of the Royal villa were reused in each of the artillery positions. And the commander seems to be quite proud of the neat result… At least the concrete was of very good quality, as today it is 100 years old and still in a nearly perfect state.

The only close-up photograph of an artillery position at Battery Aachen (1915)

The artillery positions were probably using this Krupps 15 cm gun

Under the concrete platform was a basement in which the charges (right) and the projectiles (left) were stored. These were transported on rail from the storage to the artillery position and transferred to these storage spaces through small openings in the front.  Wooden doors gave access to stairs leading down in these storage spaces.  Ammunition was raised to the gun platform through a small hand-drawn elevator.

Battery Aachen 1915 – artillery units (image: Visual Dimension bvba)

The artillery pieces were aimed at the sea, but were used only a few times to counter attacks by Allied ships.  Instead, from this position, the inland front line was bombarded regularly. The first inland bombardment on Nieuwpoort took place on May 5, 1915.

Battery Aachen 1915 – view from the artillery unit towards the sea (image: Visual Dimension bvba)

One of the 15 cm artillery guns at Battery Aachen (1915)

Today, these four artillery positions are the most authentic parts of Battery Aachen in the Raversyde open air museum, as they have not been reused in the second World War.  Two positions have been made accessible to the public, two positions are well preserved but covered by sand.

The artillery positions of Battery Aachen in their current state (photograph: Daniel Pletinckx)

The concrete structure and the attachment of the artillery piece is very well preserved. Only the entrance part has been slightly modified after September 1915 in order to be able to remain operational during attacks and bombardments.

The well preserved concrete structure of an artillery position  (photograph: Daniel Pletinckx)

The short animation below shows a bit the atmosphere of Battery Aachen and indicates briefly the sources that were used to make this virtual reconstruction.  Don’t forget that the first plane was flying in Belgium only 7 years before this scene in 1915.  The pilot, Henri Farman, was instrumental in the development of military planes in that period.  The Great War was not only cruel and insane, but also a major driver of technological development.