BASTION STAIRCASE
TILBURY FORT
ESSEX
ARCHAEOLOGICAL MONITORING
Field Archaeology Unit
March 2005
BASTION STAIRCASE
TILBURY FORT
ESSEX
ARCHAEOLOGICAL MONITORING
Prepared By:
Andrew Robertson
Position:
Project Supervisor
Signature:
Date:
Approved By:
Mark Atkinson
Position:
Unit Manager
Signature:
Date:
Doc. Ref.
1455Rep2.doc
Report Issue Date
March 2005
Circulation
English Heritage
NMR
EHER
As part of our desire to provide a quality service, we would welcome any comments you may have on the content or the presentation of this report.
Please contact the Archaeological Fieldwork Manager, at the
Field Archaeology Unit,
Fairfield Court, Fairfield Road, Braintree, Essex CM7 3YQ
fieldarch@essexcc.gov.uk
Tel: 01376 331470
Fax: 01376 331428
(c) Field Archaeology Unit, Essex County Council, c/o County Hall, Chelmsford
Essex CM1 1LF
CONTENTS
Page No.
SUMMARY
1
1. INTRODUCTION
2
2. BACKGROUND
2
2.1 Location and Geology
2.2 Archaeological and Historical Background
3. AIMS AND OBJECTIVES
3
4. METHOD
3
5. FIELDWORK RESULTS
3
5.1 Footing 1
5.2 Footing 2
6. FINDS
4
7. DISCUSSION AND ASSESSMENT OF RESULTS
4
Acknowledgements
5
BIBLIOGRAPHY
5
APPENDIX 1: CONTEXT DATA
9
APPENDIX 2: ARCHIVE INDEX
10
APPENDIX 3: EHER SUMMARY
11
FIGURES
Figure 1: Site Location
6
Figure 2: Detail of excavated footings
7
Figure 3: Sections
8
BASTION STAIRCASE,
TILBURY FORT,
ESSEX
ARCHAEOLOGICAL MONITORING
SUMMARY
Client: English Heritage
FAU Project No.: 1455
Site code: THTF 05
NGR: TQ 651 754 (Centred)
Date of Fieldwork: 17 January 2005
An archaeological watching brief was carried out on the construction of a bastion staircase at Tilbury Fort, Essex. Two footings for the staircase were machine excavated through the eastern bastion of the fort where a series of layers were observed.
The footing towards the top of the bastion was heavily disturbed by the construction of the previous staircase. However, below the disturbance was a layer of compacted silt, which may have been deposited during the early 20th century when the last phase of redevelopment of the fort took place.
The more southerly footing further down the bank revealed similar layers to those observed in the northern footing as well as a series of undisturbed stabilisation layers, of sand, chalk and clay that are either 18th or mid 19th century in date.
The layers observed in both footings seem to correlate with similar deposits identified by excavations undertaken by Newham Museum Service in between 1988 and 1995.
1.0 INTRODUCTION
This report presents the results of archaeological monitoring on the construction of a bastion staircase at Tilbury Fort. Essex County Council Field Archaeology Unit (ECC FAU) were commissioned by JGP Associates on behalf of English Heritage to undertake an archaeological monitoring exercise on the excavation of foundations for a staircase on the east bastion of the fort. The archive will be deposited at Thurrock Museum and the NMR.
2.0 BACKGROUND
2.1 Location and Geology (Figure 1)
Tilbury Fort lies on the north bank of the Thames immediately east of Tilbury Docks (TQ 651 754) and is currently being restored as a historic attraction by English Heritage. The surrounding land is a salt marsh flood plain with drift geology of brickearth (ECC 1992). The ground level of the Fort itself has been substantially increased through human activity over a number of centuries.
2.2 Historical and Archaeological Background
Tilbury Fort was constructed in the late 17th century, initially under Charles II (Scheduled Ancient Monument 26309, Essex Heritage Environment Record 1678). It replaced a smaller blockhouse built during the reign of Henry VIII in about 1540. Artillery had become the dominant weapon and the fort was built to withstand heavy bombardment. It was built in a low-lying star shape with earth embankments fronted by brick. The heaviest guns were mounted along the riverbank to protect the Thames from hostile shipping. On the landward side was a double line of moats designed to keep enemy guns at a distance. Brick revetted salient angle bastions allowed its own guns to provide complete covering fire in front of the walls. This style of fortification, known as the bastion system, was popular in Europe at the time and Tilbury is the best preserved example in Britain.
The fort was extensively modified during the late 1860s to bring it up to date for a new role as a second line of defence behind Coalhouse, Cliffe and Shornmead Forts and as a compliment to New Tavern Fort in Gravesend. It remained garrisoned into the 1920's but was never tested. A German Zeppelin shot down by its anti-aircraft guns during World War One was the only military success.
Strengthening the eastern bastion was a major part of the modifications of the 1860s with the curtain wall and bastion buried beneath earth and magazines constructed below. On top was mounted artillery that no longer faced across the river but downstream to give the maximum amount of firing time to the gunners. Further reconstruction to the eastern bastion took place in c.1903 with the mounting of 6" Mk.IV guns and their magazines (Kent 1998, 49). These gun emplacements and magazine rooms are still extant today.
Between 1988 and 1995 Newham Museum Service undertook a series of excavations and watching briefs in advance of planned works by English Heritage. The eastern bastion was investigated by two trenches, which showed a sequence of construction layers dating from the 18th century and later.
3.0 AIMS AND OBJECTIVES
The main aim of the excavation was to locate, identify and record any surviving archaeological remains. More specific aims included the identification of layers within the bastion that relate to known periods of redevelopment.
4.0 METHOD
The footprints were excavated using a 3-ton mini-digger, under archaeological supervision. Sections of these footings were recorded and a plan of their positions made. All plans were drawn at 1:20 and sections at 1:10. A photographic record comprising of colour slides and monochrome prints was maintained. The IFA standards and by-laws and ALGAO's Standards for Field Archaeology in the East of England (Gurney 2003) were adhered to during the fieldwork.
5.0 FIELDWORK RESULTS (Figs. 2 and 3)
Footing 1 was positioned against the northwest corner of the 1903 6" gun battery magazine and measured 1.5 x 1.5 x 1m deep. Footing 2 lay approximately 3.3m to the southwest of the first and again lay against the wall of the magazine. It measured 1.5 x 2.4 x 0.9m with a deeper trench of 1.5 x 0.85 x 0.4m in its centre. Both footings revealed a series of layers, which were recorded in section, and a brief description of each is presented below. Further context information can be found in Appendix 1.
5.1 Footing 1
This footing was dug below an already extant stair platform. Immediately below the turf (1) was a layer of modern rubble (2) to a depth of 0.4m. This rubble was relatively modern in date, with glass and sacking mixed in with it, and was probably associated with the construction of the extant magazine and battery in the early 20th Century. Below the rubble was a dark grey clay silt layer (3), which contained pieces of brick and glass and extended below the excavated depth.
5.2 Footing 2
Further down the bastion slope, Footing 2 revealed a series of seeming undisturbed layers. Immediately below the turf was a thin layer (4), 0.07m deep, comprising of small to medium chalky pebbles mixed with sandy loam. Below this was the same clay silt layer (3) as seen in Footing 1, but not as deep at 0.18m. This covered a 0.35m thick mid brown sandy layer (5) with pockets of deposit (3) mixed into it. These layers sealed a layer of chalky clay (6), which in turn sealed a layer of redeposited chalk (7), the full depth of which was not established.
6.0 FINDS
No finds were retrieved or samples taken from any of the groundworks, those observed being clearly modern.
7.0 DISCUSSION AND ASSESSMENT OF RESULTS
The footing excavations reveal a series of layers that would seem to broadly concur with the Newham Museum service excavations on the East Bastion between 1988 and 1995, particularly trenches 54 and 19 (Moore 2000, figs 8 & 5). The deposits uncovered in the footings are likely a series of dumped layers, which probably represents the various stages of redevelopment and cleaning out of the moats from the 18th century onwards.
Layer (3) probably represents compacted water silts and is likely to be the remains of clearing out of the moats. It is likely that this layer either postdates, or is at least contemporary with the construction of the 6" gun battery in c. 1903, as wall of the magazine does not appear to have been cut into this layer, but rather the layer mounded against it. Layer (5) is probably of a similar date to layer (3), for the same reasons, but was probably taken from a different area, possibly closer to or even on the river. Both seem comparable to the upper layers of Trench 54 (Contexts 4501 - 19) of the Newham Museum excavations.
Layers (6) and (7) seem to be earlier in date and perhapse comparable to the consolidation and stabilisation layers seen in Trench 54 at the top of the eastern bastion (Contexts 4520 -41) and Trench 19 on the Place d'Armes (Contexts 939 and 1103) excavated by the Newham Museum. The clay layer (6) seals a layer of crushed chalk (7), which extended below the depth of the excavation. Although there was no datable material recovered from either, layer the 1903 building was cut into deposit (6). If the remains are indeed comparable to those found by Newham Museum service then they probably date to the mid to late 18th century and possibly can be attributed to work done by Thomas Hyde Page in c.1778 (Kent 1998, 41). However, a later date should not be discounted as major redevelopment of the east bastion took place in the 1860's.
The layers in the footing trenches demonstrate that the ground level of the fort has been drastically increased by successive redevelopment and that stabilisation layers have been deposited, probably during the 18th or mid 19th century. The upper layers are likely to be early 20th century in date and coincide with the last phase of redevelopment at Tilbury Fort.
Acknowledgements
This project was commissioned by JGP Associates and funded by English Heritage. Especial thanks are due to the ground staff of T. Butler & Son who provided assistance throughout the fieldwork. Mr M. Atkinson managed the project and the fieldwork was carried out by the author.
BIBLIOGRAPHY
Essex County Council
1992
The Essex Environment: A report on the state of the County's Environment ECC Planning Department
Kent, P.
1998
Fortifications of East Anglia Terance Dalton
Moore, P.
2000
Tilbury Fort: a post-medieval fort and its inhabitants Post Medieval Archaeology 34, 3 - 104
Peachy, M.
2003
West Powder Magazine Roof, Tilbury Fort, Essex, Building Recording ECC FAU Client Report
Peachy, M.
2003
East Powder Magazine Roof, Tilbury Fort, Essex, Building Recording and Watching Brief ECC FAU Client Report
APPENDIX 1 - CONTEXT DATA
All dimensions are given in metres
All layers are greater than 1.5m wide
Context
Type
Length
Depth
Description
1
Turf
-
0.2
Turf and a thin layer of light brown sandy topsoil
2
Layer
+1.5
0.5
Modern rubble containing plastic and sacking
3
Layer
+7.2
+0.4/ 0.18
Dark grey silty clay layer - possibly compacted water silt
4
Layer
+2.4
0.07
Layer of chalky pebbles mixed with l. brown sandy topsoil
5
Layer
+2,4
0.35
Mid brown sandy silt with patches of 3 mixed in
6
Layer
+2.4
0.26
Mid grey chalky clay
7
Layer
+2.4
+0.3
Light grey redeposited chalk with silt mixed in
APPENDIX 2: ARCHIVE INDEX
SITE NAME: Bastion Staircase, Tilbury Fort
Index to the Archive
File containing:
1. Research Archive
1.1 Client Report
2. Site Archive
2.1 1x Context Register
2.2 7 x Context Sheets
2.3 1 x Section Sheet
2.4 1 x Plan Sheet
2.5 2 x Photo Registers
2.6 3 x Colour slides
2.7 3 x B + W prints
No artefacts
APPENDIX 3: EHCR SUMMARY SHEET
Site Name/Address:
Bastion Staircase, Tilbury Fort
Parish:
East Tilbury
District:
Thurrock
NGR:
TQ 651 754 (Centred)
Site Code:
THTF 05
Type of Work:
Watching Brief
Site Director/Group:
Andrew Robertson
ECC FAU
Date of Work:
17th January 2005
Size of Area Investigated:
Approximately 5.85m�
Location of Finds/Curating Museum:
Thurrock Museum
Funding Source:
English Heritage.
Further Work Anticipated?
No
Related EHCR Nos:
Final Report: EAH Summary?
Periods Represented: Post-medieval; Modern
SUMMARY OF FIELDWORK RESULTS:
An archaeological watching brief was carried out on the construction of a bastion staircase at Tilbury Fort, Essex. Two footings for the staircase were machine excavated through the eastern bastion of the fort where a series of layers were observed.
The footing towards the top of the bastion was heavily disturbed by the construction of the previous staircase. However, below the disturbance was a layer of compacted silt, which may have been deposited during the early 20th century when the last phase of redevelopment of the fort took place.
The more southerly footing revealed similar layers to those observed in the northern footing as well as a series of undisturbed stabilisation layers that are either 18th or mid 19th century in date.
The layers observed in both footings seem to correlate with similar layers identified between 1988 and 1995 in excavations undertaken by Newham Museum Service.
Previous Summaries/Reports:
Author of Summary:
Andrew Robertson
Date of Summary:
March 2005
1455
Site Name
Archaeological Evaluation Report
Prepared for Client Name
3
4
20 King Street, Saffron Walden
Archaeological Excavation
Prepared for Coalhouse Properties Ltd
1
Bastion Staircase, Tilbury Fort
Archaeological Watching Brief
Prepared for English Heritage
8
9
11