Buiten de Waterpoort 2 – 6 (2016−2017)

Photo: SOB Research, Heinenoord.

In the period from 21 to 25 November 2016 and 13 to 17 March 2017, SOB Research archaeological research carried out in the form of an Inventory Field Survey by means of Test Trenches and Archaeological Supervision of the construction of a building pit at the site of the plan area Buiten de Waterpoort 2 – 6.

The research was carried out in the context of the permit conditions for the construction of a hotel. The surface area of ​​the plan area is approximately 1250 square meters. The surface area of ​​the research area is approximately 470 square meters. This concerns the construction pit for the new hotel, with a size of approximately 43 by 11 meters.

Overview map of the research area

The construction pit has been constructed to a depth of 2.47 metres +NAP (approximately 3.6 metres below the top of the existing dike body). From that level, foundation trenches will be dug to a depth of 1.97 metres +NAP. Based on verbal information, piles will be installed between the construction of the construction pit and the digging of the foundation trenches to a depth of approximately 18 metres below the level of the construction pit.

Conclusions

Based on the results obtained from the research, the following conclusions can be drawn:

1. The soil structure in the research area up to the constructed building area at approximately 2.47 metres +NAP concerns exclusively anthropogenic fill layers, consisting of sand packages with rubble fragments, lime fragments and pebbles and layers with brick rubble. In the research area, the anthropogenic fill layers slope in a northerly direction, which means that the stratigraphy can be interpreted as a raised dike body. The top of the possibly natural Tiel Deposit was possibly reached in the boring (Boring no. 10) at a depth of 2.90 metres below the constructed area (2.47 metres +NAP), at 0.43 metres -NAP. This concerns a fairly clean grey clay layer. At this profile, the package of fill layers has a thickness of at least 5.90 metres. During research in the Emperor Street 1Smole, L. & J. Dijkstra (2005)
   Gorinchem, excavation Keizerstraat 2a, ADC Report 349, Amersfoort.
   PDF (3 MB) and the Bale Alley 2S. Gerritsen, with contribution by RF van Dijk
   Final research at Balensteeg 18 – 24, municipality of Gorinchem ; Zaandijk ; 2007 ; Hollandia series no. 54.
   Download (7,12 MB)
    a similar clay layer was found at a level of 0.90 meters -NAP and 0.70 meters -NAP respectively. In the Balensteeg this clay layer was above a raised layer from the 14^de century with brick and slate fragments and is therefore also interpreted as a raised layer. It cannot be ruled out that the grey clay layer found in Boring no. 10 at 2.90 metres below the surface is also a raised layer. Finally, in the other boreholes carried out, brick was drilled at much deeper levels, to a maximum depth of 5.15 metres below the surface (2.87 metres -NAP).
2. Within the research area, remains of (sub-)recent foundations and a floor were found. These are foundations made of brick and concrete and a floor of cement/​concrete. These archaeological traces can be interpreted as remains of buildings from the second half of the 20^e century.
3. Within the research area, remains were found of a round fortress tower, the city wall and a possible building on the inside of the city wall. On the inside of the city wall, brick parapet arches and a possible staircase construction were also found, which are related to the parapet on the inside of the city wall. Six loopholes finished with natural stone were found in the city wall and the tower.

Rear view of a loophole

The brick structures of these defensive works have been preserved in situ up to a maximum height of 3.28 metres +NAP (approximately 0.80 metres above the bottom of the newly constructed excavation pit) and are probably still present at a depth of at least 3.0-4.0 metres below the bottom of the excavation pit. The archaeological remains mentioned concern the remains of the first stone-built city wall of Gorinchem. It is known that from around 1382, after the granting of city rights, the earthen city walls of Gorinchem were replaced by a stone wall. The archaeological remains found can therefore be dated to the last part of the 14^de century, which is confirmed by the size of the bricks used and the stonemason's marks on the natural stone. It is possible that the part of the late medieval fortifications that was found later also served as a boundary for the forecourt of the castle complex of the Blauwe Toren (Blue Tower), that in the second half of the 15^de century commissioned by Charles the Bold has been constructed.

Detailed map circa 1600 showing remains of the Blue Tower and the old ramparts

The part of the late medieval fortifications found during the research is still shown on an old map from 1592 and was briefly maintained as a city wall after the demolition of the castle. Around 1612 the late medieval fortifications had completely disappeared and at the location of the research area there was a dike body with a quay, including a wide heul (an underpass under the quay)

Recommendations

Based on both the physical and the substantive criteria, as laid down in the subprocess Evaluating the KNA 4.0, Appendix IV, there is an archaeological site that is considered worthy of preservation.

• Establishing a contour of the existing foundation layers under the fortress tower and the city wall by means of drilling soil did not lead to the desired result. However, it can be concluded on the basis of the drillings that were carried out that the rising masonry of both the tower and the city wall is still present in the subsoil to a depth of at least 3.20 to 4.00 metres below the constructed surface. Indicating a contour of foundation layers around the fortress tower and city wall, mainly to be able to determine where piles can be placed without damaging the archaeological remains, is not really possible on the basis of the results obtained from the drillings. At the drilling depths reached, it is not possible to determine with certainty whether the drilling has come across a foundation layer, a piece of rubble or a loose brick. This method with drilling soil and the results obtained from it offer an insufficient and certainly not reliable basis on which to base an adjusted pile plan. Therefore, it is advised to use research, other than drilling, to obtain more certainty regarding the contour of the foundations under the tower and the city wall. Mechanical stone drilling could provide more clarity for determining the exact depth of the bottom of the city wall and the tower and the width of the foundation layers;
• It is recommended that the digging of the foundation trenches be carried out under archaeological supervision;
• Given the nature of the archaeological site, which is worth preserving, it is recommended that it be preserved in situ as much as possible and, where possible, that the construction plan be adapted in such a way that preservation in situ is guaranteed;
• In order to guarantee preservation in situ in the future and to prevent further damage to the archaeological remains, it is recommended that the site be granted the status of municipal archaeological monument.