Research Heritage Bursary 2017 Project Report Roscommon Crucifixion Plaques - Project funded by The Heritage Council & Roscommon County Council

Research Heritage Bursary 2017
                             Project Report
                Roscommon Crucifixion Plaques

Project funded by The Heritage Council & Roscommon
                   County Council
https://sketchfab.com/roscommon3d/collections/roscommon3d-crucifixion-plaques

Introduction
The Roscommon County Council Research Bursary was sought to undertake and complete digital survey
work on the seven crucifixion plaques that have been identified in Co. Roscommon. The crucifixion
plaques were recorded using a non-invasive digital recording method known as laser scanning.
The proposed methodology (laser scanning) is well established in the documentation of cultural heritage
and archaeological monuments and remains. This is due largely to its non-invasive nature and the highly
accurate outputs that highlight surface geometries that would not otherwise be visible under visual
assessment. 3D data is therefore used to measure buildings, identify faded details and to record the rate
of erosion and weathering of objects and features. The precise surface measurements recorded during
data capture ensures a true replica of the object under assessment is created which can be used as a
reference for ongoing and future conservation efforts and applications.

Aims and Objectives
Non-invasive digital recording methods were undertaken to:
       Assess current condition of crucifixion plaques in Co. Roscommon
       Create high quality, scaled models of crucifixion plaques that can be used for ongoing/future
        conservation works and applications
       Create an extensive bibliography on crucifixion plaques and iconography in and Irish context
       Create open access archive of the 3D models and historical information pertaining to the plaques
       Disseminate 3D models online for use in teaching and learning outcomes, and to promote
        Roscommon’s cultural heritage collections

Site Selection
This research bursary was sought to undertake and complete work on seven crucifixion plaques that
have been listed in the SMR for County Roscommon in order to provide an accurate basis for comparison
with other examples identified nationally. These sites included:
       Ballypheasan (RO039-043005-)
       Cloonshanville (RO015-023----)
       Creevy (RO013-037----)

   Sraduff (RO051-072002-)
       Tibohine
       Toberelva (RO027-029005-)
       Tulsk (RO022-114014-)

                            Figure 1 Distribution map of Roscommon crucifixion plaques

The Tibohine crucifixion plaque was subsequently omitted from the data set as access could not be
obtained within the requisite timeframe. However, two additional crucifixion plaques were later added
to the data set including a large plaque at Ardcarn Church of Ireland church (RO006-103005-), and a
second crucifixion plaque at Tulsk Dominican Friary (RO022-114015).

Survey Methodology
Site visits were undertaken in advance of digital surveys to establish the general condition of the
monuments under assessment, and to evaluate accessibility.

The crucifixion plaques were scanned using the Artec Eva structured light scanner. This scanner can
capture and simultaneously process up to two million points per second with up to 0.1mm accuracy
ensuring the capture of precise measurements at high resolution. This scanner is equipped with a
mounted camera and has a working distance of 40-100cm, producing 1.3mpg texture outputs. The
scanned frames are aligned automatically in real-time using target and target texture detail for tracking.
This streamlines the process of obtaining accurate colour and texture details.

Figure 2 Artec Eva Scanner set up

Weather conditions varied throughout the recording process and in most instances required the use of a
tarp. In order to produce optimal 3D data, poor or uneven lighting must be avoided therefore the use of
a tarp mitigated any lighting issues from the beginning of the scanning process. This insured accurate
digital surveys were undertaken and streamlined the recording process considerably.

                             Figure 3 Tarp being used to omit light during scanning

Data acquisition time varied based on monument size and due to changeable weather conditions however
on average took 1.5 hours per monument including standard recording methods. A recording sheet was
completed for each of the plaques surveyed in this project and is based on the example produced by the
Roscommon3D project.

3D models were processed using Artec Studio Professional scanning software packages and prepared for
export. The resulting digital atrefacts were published using an online publishing platform known as
Sketchfab.

Research Outputs and Dissemination
This project used up-to-date digital methods of dissemination in tandem with traditional
archaeological reporting and community outreach as a means of knowledge transfer.

Social media platforms were utilised throughout the project to ensure maximum visibility of the
research being undertaken and to highlight best practice methods for recording commemorative stone
monuments in a range of environments and conditions. Social media platforms used included:

       Twitter
       Facebook
       Instagram
Each platform was used to target a number of different demographics and were complimented by
more detailed field diary reports shared via a website blog.

                    Figure 4 Sketchfab account and crucifixion plaque collection without textures

All 3D models produced in this survey were shared online using Sketchfab. Sketchfab is an interactive
platform that allows users to upload and annotate a range of 3D data and models for teaching and
learning, engagement, and dissemination. Digital artefacts hosted on Sketchfab can be easily
embedded in websites and shared across social media platforms, and can be viewed using a range of
handheld devices.

                 Figure 5 Tour participants exploring Roscommon3D collections during Heritage Week

Further to the digital dissemination methods utilised in this project, more traditional forms of
dissemination were undertaken including guided tours and presentations to the public during heritage
week, followed by a discussion on the principles of digital recording methods to the Digital Arts and
Humanities Masters class at University College Cork. A comprehensive catalogue of the Roscommon
Crucifixion plaques will be submitted to the ‘Journal of the County Roscommon Historical and
Archaeological Society’ which will discuss the Roscommon catalogue within the broader context of the
Irish crucifixion plaque tradition.

Bibliography
Foley, C. and McHugh, R. (2014) The Archaeological Survey of County Fermanagh. Belfast.

Harbison, P. (1995) A Crucifixion Plaque in Stone?. Archaeology Ireland, Vol. 9, No. 2. pp. 11-12

Harbison, P. (1984) The Bronze Crucifixion Plaque Said to be from St. John's (Rinnagan), near Athlone.
The Journal of Irish Archaeology, Vol. 2. pp. 1-17

Kelly, D. (1990) Crucifivion Plaques. Irish Arts Review Yearbook. pp. 204-209

Longfield, A.K. (1946) Some 18th Century Irish Tomb-Stones. The Journal of the Royal Society of
Antiquaries of Ireland. Vol. 76, No. 2, pp. 81-88

Mulhall, J. (1907-09) Ardcarn Churchyard. Journal of the Association for the Preservation of the
Memorials of the Dead, Ireland. Vol 7. pp 453-4

O’Flanagan, Rev. M. (1931) Letters containing information relative to the antiquities of the county of
Roscommon collected during the progress of the Ordnance Survey in 1837. Bray.

Ó Riain, P. (2011) A dictionary of Irish Saints. Dublin. Four Courts Press.

Phelan, M.M. (1996) The O'Kerin School of Monumental Sculpture in Ossory and Its Environs in the
Sixteenth and Seventeenth Centuries. The Journal of the Royal Society of Antiquaries of Ireland, Vol.
126, pp.167-181

Timony, M.A. (1980) Two stone crucifixion plaques from east Connaught. In H. Murtagh (ed.). Irish
Midland Studies: Essays in Commemoration of N.W. English. Old Athlone society. pp142-6

Timony, M.A. (1982) Roscommon Crucifixion Plaques – A Detective Story. In M. Fitzmaurice (ed.)
Roscommon Association Yearbook. pp.8-9

Timony, M.A. (2011) Grave Memorials in Tibohine Old Graveyard, Co. Roscommon. Tibohene
Centenary Celebrated, 1911-2011. pp16-18

Timony, M.A. (2013) Notable 18th and 19th century memorials in Tibohine Old Graveyard, Co.
Roscommon. Journal of the Roscommon Historical and Archaeological Society, vol. 12, pp.39-44

Tonra, H. (1998) Ardcarne. Journal of the Roscommon Historical and Archaeological Society, Vol. 7.
pp.55-57

Table 1 Artec Eva Specifications

                                        General specifications

                               3D resolution, up to            0.5 mm
                               3D point accuracy, up to        0.1 mm
                               3D accuracy over            0.03% over 100
                               distance, up to                   cm
                               Colors                          24 bpp
                               Texture resolution              1.3 mp
                               Scanning technology          structured light

                               Structured light source      flash bulb (no
                                                                laser)

                               Working distance                0.4 – 1 m
                               Linear field of view, HxW    214 × 148 mm
                               @ closest range
                               Linear field of view, HxW    536 × 371 mm
                               @ furthest range

                               Angular field of view,          30 × 21°
                               HхW
                               Video frame rate, up to          16 fps
                               Exposure time                 0.0002 sec.
                               Data acquisition speed,      2 mln points /
                               up to                             sec.
                               Multi core processing             Yes
                               3D formats                  OBJ, PLY, WRL,
                                                             STL, AOP,
                                                            ASCII, Disney
                                                             PTEX, E57,
                                                              XYZRGB
                               Formats for                 CSV, DXF, XML
                               measurements
                               Processing capacity         40 mln triangles /
                                                              1 GB RAM

Table 2 Crucifixion & Armorial plaques included in this survey

      Name                      Location                         SMR   Image

 Ballyphesean         Church Lane                      RO039-043005-

 Creevy               Roman Catholic church of         RO013-037----
                      Liscaul

 Cloonshanville Cloonshanville Abbey                   RO015-023----

 Sraduff              St. Ronan's Holy Well            RO051-072002-

Name           Location               SMR        Image

Tulsk       Tulsk Dominican Friary   RO022-114014-

Toberelva   Roman Catholic Church    RO027-029005-
            of Toberelva

Name          Location        SMR        Image
Ardcarn    Ardcarne roman    RO006-103005-
           Catholic Church