Placetron wosnessenskii: Scaled Crab–The race Rocks taxonomy

We are awaiting positive identification on this one as we do not see these often while diving at Race Rocks. This photo was by Pearson College Divers in the spring of 2007,
spring, 2007
Domain Eukarya
Kingdom Animalia
Phylum Arthropoda
Class Malocostrac
Subclass Eumalacostraca
Superorder Eucarida
Order Decapoda
Suborder Pleocyematya
Infraorder Anomura
Superfamily Paguroidea
Family Lithodidae
Genus Placetron
Species wosnessenskii
Schalfeew,1892
Common Name: Scaled Crab 

 

Other Members of the Phylum Arthropoda at Race Rocks 
taxonomyiconReturn to the Race Rocks Taxonomy
and Image File
pearsonlogo2_f2The Race Rocks taxonomy is a collaborative venture originally started with the Biology and Environmental Systems students of Lester Pearson College UWC. It now also has contributions added by Faculty, Staff, Volunteers and Observers on the remote control webcams.

 2007 (PC)

Race Rocks Lighthouse Great Race Island, British Columbia DFRP # 17447 Condition Assessment Including Indicative Cost Estimate: 2007

This document was prepared two years before  DFO actually did the upgrading of the light tower. The following quotes on the historic significance is worth noting.

 

The Race Rocks tower is located on Great Race Island, a small and barren rock outcrop in the Strait of Juan de Fuca, about fifteen kilometres south of Victoria, British Columbia. Erected in 1860, simultaneously as Fisgard light, with which it was designed to function, the Race Rocks light tower is British Columbia’s second oldest operating lighthouse and a forerunner of the extensive system of navigational aids built during the following century along Canada’s West Coast.

Construction of both the Fisgard and Race Rocks towers was undertaken in 1859, at the initiative of colonial officials and with partial financial and technical support of the Imperial Government. The latter provided its expertise, the lighting apparatus, which according to the local legend, would have travelled from England with Fisgard’s first light keeper, and 7000 pounds in funding, half as a grant, half as a loan. The colonial government oversaw the selection of the site and the construction following a plan of combined tower and dwelling, attributed to both JohnWright of London and to the Surveyor General of British Columbia, Joseph Pemberton.1

  “Race Rocks light tower is “the only known example of tall, pre-Confederation, unsheathed stone masonry tower, built outside of Ontario”.2 Along with towers of a similar design on the Great Lakes, it shares the classification of “Imperial” tower, a reference to its typology as a tall, tapered, circular, pitched-faced stone structure, rather than to the British involvement in its construction. Unlike the Imperial towers of Ontario, however, the interior configuration of the Race Rocks lighthouse was based on its being attached to the keeper’s residence, and consists of a continuous stone spiral staircase rather than of superposed wooden floors linked by ladders.

The light at Race Rocks was lit on December 26, 1860, a month after that of the Fisgard tower. Until the construction of the landfall light at Carmanah Point in 1891, it was considered the most important lighthouse in British Columbia. It was attended to by a long succession of light keepers and their families, who lived in the attached stone residence until the construction of new dwellings in 1964, closely followed by the demolition of the original house in 1967.”

EXECUTIVE SUMMARY Background

race-rocks-towerThe Heritage Conservation Network (HCN) project team has completed the condition assessment and report for the Race Rocks Lighthouse located on Great Race Island in the Juan de Fuca Strait, south of Victoria, British Columbia, as part of the project for eighteen lighthouses for the Department of Fisheries and Oceans (DFO). The report contains structural and building envelope conditions, analysis of these conditions, recommendations and indicative cost estimates for mandatory and cyclical conservation work both in the short and the long term.

See the Full PDF at :Condition Assessment

Conservation Approach

This condition assessment, report and related recommendations, follow the conservation approach of minimal intervention and least harm to preserve/protect heritage character. This approach will help provide DFO with information required to properly manage the Race Rocks lighthouse while ensuring that the building is safe in terms of both public and staff and that the existing heritage fabric will be protected and maintained.

Description

The Race Rocks Lighthouse is a pitched-face stone structure with a round, tapered shaft, painted with a series of horizontal black and white painted stripes. The tower corbels at the top forming a gallery around the cast iron lantern, which rises approximately 32 meters (105′-0″) tall from grade, and tapers from a diameter of approximately 5.8 meters at its base to 3.8 meters at its narrowest point below the gallery. The tower is accessible through a curved metalic stair and arched door opening, located 3.20 meters (10’6″) above grade. It is pierced with 4 window openings, the two lowest of which are arched and the top two, rectangular. The cast iron octagonal lantern, which sits atop the concrete parapet, can be reached by a continuous stone spiral staircase, which terminates just below it.

Heritage Value

The Race Rocks Lighthouse is a Recognized federal heritage building (FHBRO log number 90-85). It obtained a total score of 62, based on a score of 14 for historical associations, 23 for architecture, and 25 for environment. A review of the related Heritage Character Statement is provided in the report to help the lighthouse custodians identify and protect heritage fabric and aid in guiding future maintenance and repair interventions so as to maintain the lighthouse’s heritage value. This section identifies all of the elements of the lighthouse that are important in defining the overall heritage values that require protection. Its character-defining elements reside in its robust stonework construction consisting of large rusticated blocks with limited decorative detailing, typical of “Imperial” lighthouse design, in its black and white day marking and in the interior spiral stone stairway. Other buildings on the islands are considered to contribute to the heritage character of the tower’s environment, but were not investigated for this report.

PWGSC, P&TSM, Heritage Conservation Network 1

Race Rocks Lighthouse Condition Assessment Reports Victoria, British Columbia Including Indicative Cost Estimate

Methodology

Background and historical documentation were consulted both before and after the on-site investigation. This included a review of documents related to environmental site assessments in the preparation of the Site Specific Safety Plan prior to the site visit. The on-site investigation consisted of a preliminary site orientation by the team members to gain a general understanding of the building and its surroundings. Detailed visual and tactile investigations were then carried out on both the exterior and interior of the lighthouse. All investigations were non-destructive by nature and any samples were gathered from loose or fallen materials.

Assessment

Building Structure:
Overall, the stone walls from the foundations to the top of the tower were found to be in fair to poor condition. Although there are no signs of displacements or structural instability, extensive damage was observed. Two large vertical cracks extend vertically from the base of the tower to a height of approximately 10 meters and will require mapping and monitoring. Deterioration of the stone also included delamination and salt formation, mostly visible on the interior walls, at the top of the tower, corresponding to exterior areas that were covered in “gunite” several decades ago. Water appears to be trapped in the walls at that level and the stone masonry will require rapid treatment in the affected area to limit further decay. Extensive cleaning, repointing and renewal of the impervious coating will also be required throughout.

Lantern and Gallery:
Deferred maintenance of the lantern and gallery has lead to deterioration of surfaces, with paint chipping and corrosion of the cast iron lantern and paint failure and concrete spalling of the underlying parapet. The gallery also shows traces of surface deterioration, with decayed paint and a failing membrane.

Building Envelope:
With the exception of an opening obstructed with fog-detection equipment, windows and the access door were found to be in good condition overall. The main recommendation with regards to the building envelope concerns the improvement of ventilation and heating levels to help resolve the stone deterioration on the interior face of the walls. Ventilation may for instance be provided through the windows and door openings.

Other Building Elements:
The exterior stair is a recent addition to the structure and is in good condition overall. It may warrant replacement in the future for reasons of code compliance and enhancement of the structure’s heritage character.

2 PWGSC, P&TSM, Heritage Conservation Network

Race Rocks Lighthouse Condition Assessment Reports Victoria, British Columbia Including Indicative Cost Estimate

Recommendations

The principal recommendations for this condition assessment would include:

  • Examine and monitor the two vertical cracks at the base of the tower for a minimum of 1-2 years to verify if they are still active and identify their cause(s).
  • Remove the “gunite” coating from the top of the exterior walls using an appropriate method.
  • Clean, repair and repoint the stone on both interior and exterior faces of the tower.
  • Remove all paint on the interior of the tower, using an appropriate non-abrasive method.
  • Replace the existing impervious coating with a coating that allows circulation of water vapour and repaint the existing daymarking.
  • Remove and repair the cast iron lantern (workshop conservation).
  • Repair of the top of the parapet, at the base of the lantern.
  • Provision of additional ventilation and heating inside the tower.
  • Implement regular maintenance activities. A detailed list of recommendations, identifying the recommended short- or long-term time frame is provided by building element in Section 4.0 and by type (mandatory, cyclical, investigation). Further investigation into building elements that were not accessible, research, and monitoring of conditions will also be an important future activity.

    Cost Estimates

    The estimated cost for all recommended mandatory and cyclical work for the next twenty-five (25) years is $3,503,600. The corresponding Net Present Value (NPV) is $1,782,000.

    This amount corresponds to the sum (in NPV) of the mandatory generally short-term work $598,000, the cyclical generally long-term work $653,000 while also providing an allowance of $76,000 for further essential investigation, monitoring, and research, and $455,000 for overall fees, administration, etc.

    The cost estimates for a Five Year Operating and Maintenance Plan, as provided by DFO, are included in Appendix J.

Race Rocks Lighthouse Victoria, British Columbia

Condition Assessment Reports Including Indicative Cost Estimate

TABLE OF CONTENTS

EXECUTIVE SUMMARY ……………………………………………………………………………………………..1

1.0 INTRODUCTION………………………………………………………………………………………………..5

  1. 1.1  Background……………………………………………………………………………………………….5
  2. 1.2  Historic Context …………………………………………………………………………………………5
  3. 1.3  Conservation Approach ………………………………………………………………………………9
  4. 1.4  Project Team ……………………………………………………………………………………………11

2.0 LIGHTHOUSE DESCRIPTION…………………………………………………………………………12

  1. 2.1  Construction of the Lighthouse……………………………………………………………………12
  2. 2.2  Evolution of the Lighthouse ……………………………………………………………………….13

3.0 HERITAGE VALUE ………………………………………………………………………………………….17

4.0 CONDITION OBSERVATIONS, ASSESSMENT AND RECOMMENDATIONS …18

  1. 4.1  Methodology …………………………………………………………………………………………….18
  2. 4.2  Building Structure ……………………………………………………………………………………..19
    1. 4.2.1  Foundation …………………………………………………………………………………….19
    2. 4.2.2  Wall Structure ………………………………………………………………………………..24
    3. 4.2.3  Floor Structure and Interior Stair ………………………………………………………34
  3. 4.3  Lantern and Gallery ………………………………………………………………………………….38
  4. 4.4  Building Envelope …………………………………………………………………………………….46
    1. 4.4.1  Exterior Walls and Roof ………………………………………………………………….46
    2. 4.4.2  Windows……………………………………………………………………………………….49
    3. 4.4.3  Doors…………………………………………………………………………………………….52
  5. 4.5  Other Building Elements ……………………………………………………………………………54

5.0 ISSUES ANALYSIS …………………………………………………………………………………………..56

  1. 5.1  Health and Safety ………………………………………………………………………………………56
  2. 5.2  Protection of Heritage Character …………………………………………………………………56
  3. 5.3  Site-Specific Challenges to Future Planning Work ………………………………………..56
  4. 5.4  Materials Conservation Specialists Required ………………………………………………..57
  5. 5.5  Need for a Regular Maintenance Program ……………………………………………………58

6.0 URGENT WORK TO PROTECT THE PUBLIC AND STAFF …………………………..59

PWGSC, P&TSM, Heritage Conservation Network i

Race Rocks Lighthouse Condition Assessment Reports Victoria, British Columbia Including Indicative Cost Estimate

7.0 LONG-TERM CONSERVATION PROJECT PLAN AND
OPERATING AND MAINTENANCE PLAN
……………………………………………………..60

  1. 7.1  Urgent Work to Protect Heritage Character ………………………………………………….60
  2. 7.2  Recommendations for Further Investigation, Including Testing and Recording…60
  3. 7.3  Twenty-five Year Mandatory and Cyclical Long-term Repairs/Replacements ….61
  4. 7.4  Five Y ear Operating and Maintenance Plan ………………………………………………….63
  5. 7.5  Schedule…………………………………………………………………………………………………..63

8.0 COST ESTIMATES …………………………………………………………………………………………..64

  1. 8.1  Twenty-five Year Project Plan ……………………………………………………………………65
  2. 8.2  Five Year Operating & Maintenance Plan…………………………………………………….66
  3. 8.3  Demolition Option and Due Diligence …………………………………………………………66

APPENDIX A: APPENDIX B: APPENDIX C: APPENDIX D: APPENDIX E: APPENDIX F: APPENDIX G: APPENDIX H: APPENDIX I: APPENDIX J:

Reference Documents ……………………………………………………………………….. A-1

FHBRO Heritage Character Statement, Score and Building Report ……B-1

The Stone Tower………………………………………………………………………………..C-1

Supplementary Chronology of Historical Information ………………………. D-1

Archival Drawings……………………………………………………………………………..E-1

Executive Summaries of Environmental Assessment Reports……………… F-1

Site Specific Safety Plan ……………………………………………………………………. G-1

Field Observations……………………………………………………………………………. H-1

Detailed Cost Table for all Recommendations ……………………………………..I-1

Five Year Operating and Maintenance Plan ………………………………………..J-1

See the Full PDF at :Condition Assessment