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1 Alberta Human Services, Occupational Health and Safety
UTILITY POLE COLLAPSE
Type of Incident: Fatal
Date of Incident: September 10, 2011
File: F 6183257
Alberta Human Services, Occupational Health and Safety
TABLE OF CONTENTS
SECTION TITLE PAGE NUMBER
1.0 DATE AND TIME OF INCIDENT 3
2.0 NAME & ADDRESS OF PRINCIPAL PARTIES 3
2.1 Owner 3
2.2 Prime Contractor 3
2.3 Employer(s) 3
2.4 Contractor(s) 3
2.5 Supplier(s) 3
2.6 Workers(s) 3
2.7 Others
3.0 DESCRIPTION OF PRINCIPAL PARTIES 4
3.1 Employers 4
3.2 Worker 4
4.0 LOCATION OF INCIDENT 4
5.0 EQUIPMENT, MATERIAL AND OBSERVATIONS 4
5.1 Equipment and Material 4
5.2 Observations 5
6.0 NARRATIVE DESCRIPTION OF INCIDENT 5
7.0 ANALYSIS 7
7.1 Direct Cause 7
7.2 Contributing Factors 7
8.0 FOLLOW-UP/ ACTION TAKEN 7
8.1 Human Services, Occupational Health and Safety 7
8.2 Industry 8
8.3 Additional Measures 8
9.0 SIGNATURES 10
10.0 ATTACHMENTS 10
File: F 6183257
Alberta Human Services, Occupational Health and Safety
SECTION 1.0 DATE AND TIME OF INCIDENT
1.1 September 10, 2011 at approximately 3:35 p.m.
SECTION 2.0 NAME AND ADDRESS OF PRINCIPAL PARTIES
2.1 Owner(s)
2.1.1 Altalink, L.P.
2611 – 3rd
Avenue SE
Calgary, Alberta, T2A 7W7
2.2 Prime Contractor
2.2.1 Altalink, L.P.
2611 – 3rd
Avenue SE
Calgary, Alberta, T2A 7W7
2.3 Employer(s)
2.3.1 Galbraith Power (BC) Inc.
1115 -1608 Broadway Street
Port Coquitlam, BC V3C 2M8
2.3.2. Empirica Energy Inc.
3116 Suite C, 16th
Avenue North
Lethbridge, AB T1H 5J6
2.4 Contractor(s)
2.4.1 Greely Rock Ltd.
Box 2072
Revelstoke, BC V0E 2S0
2.5 Supplier(s)
2.5.1 Poletec Industries Ltee./Ltd.
10440 Rue Henault
Montreal Nord, Quebec H1G 5R4
2.6 Worker(s)
2.6.1 Evan Horkoff, Galbraith Power (BC) Inc., Apprentice Lineman
177 Silverado Range Cove SW
Calgary, AB, T2X 0E1
File: F 6183257
Alberta Human Services, Occupational Health and Safety
2.7 Others
2.7.1 RCMP Crowsnest Pass Detachment
SECTION 3.0 DESCRIPTION OF PRINCIPAL PARTIES
3.1 Altalink L.P., an Alberta based large power Transmission Company with more than
600 workers, owns, operates and maintains power lines and was the prime contractor
at the site. Altalink L.P. contracted Empirica Energy Inc. to refurbish part of the 170
L power line including Structure 29.
3.2 Galbraith Power (BC) Inc. was the employer of the deceased worker. On September
9, 2011, the day before the incident, Empirica Energy Inc. and Galbraith Power (BC)
Inc. were amalgamated under the name Galbraith Power (BC) Inc. The amalgamated
Corporation was registered with the British Columbia Registry Services on October 1,
2011. On December 16, 2011, Galbraith Power (BC) Inc. changed its name to
Rokstad Power Corporation in Alberta.
3.3 Prior to restructuring, Empirica Energy Inc. hired a small company, Greely Rock Ltd.
to provide safe access to the sites (scaling) and to drill holes into the rocks to facilitate
the installation of anchors. Greely Rock Ltd., worked under the civil division of
Empirica Energy Inc.
3.4 Poletec Industries Ltee./Ltd., was the supplier of the Tri-Anchor pole mount system
designed to secure utility poles in rocky terrain.
3.5 The fatally injured worker (Evan Horkoff) was a first year lineman apprentice. He
started his apprenticeship on August 2, 2011.
SECTION 4.0 LOCATION OF INCIDENT
The incident occurred at a location approximately 1 km east of Blairmore, Alberta, at
Structure 29 of power line 170 L. Structure 29 was located in rocky, mountainous
terrain above Highway 3 (Refer to Attachment A-Map and Attachment B-
Photographs 1, 2, 3 and 4).
SECTION 5.0 EQUIPMENT, MATERIAL AND OBSERVATIONS
5.1 Equipment and Material
5.1.1 Two wooden poles were part of a temporary structure built to facilitate the removal of
conductors and cross braces from the existing power line poles that were scheduled
for replacement. The conductors had been de-energized.
File: F 6183257
Alberta Human Services, Occupational Health and Safety
5.1.2 The temporary wooden pole involved in the incident was approximately 17 meters
high and weighed 880 kilograms. There was a 3.1 meter long sling attached to the
pole near the top end. A No.9 Tri-Anchor pole mount system was used to secure the
temporary wooden poles to the ground. Galbraith Power (BC) Inc. installed two guy
wires on each of the two temporary poles and a bridal guy wire between the two poles
to provide structural stability.
5.1.3 The No.9 Tri-Anchor pole mount system was designed to be used in solid rock. The
system consisted of modules with hollow metal tubes (sleeves) that, when bolted
together form a tight collar encircling the butt of the pole. According to the
manufacturer’s specifications, rock anchors extend through the sleeves and into .61
meter deep holes pre-drilled into rock. The anchors have expansion shells on the
bottom ends which are inserted into holes drilled into the rock. When the nuts on the
top of the anchors are tightened, the expansion shells expand, to secure the anchors.
The number of modules required depends on the diameter of the pole butt (Refer to
Attachment C- Tri-Anchor manufacturer’s specifications).
5.1.4 The pole mount system at the location did not have Tri-Anchor anchors. Instead, it
was secured to the rock by No.8 DYWIDAG thread bars inserted into 6 foot deep
holes drilled into the rock. The collar was made up of 4 modules. Four DYWIDAG
thread bars were inserted through the hollow metal tubes and into the holes. There
were no expansion shells at the bottom of the DYWIDAG thread bars. Each
DYWIDAG thread bar had a nut on the top end of the module. In addition two of the
thread bars had a bolt at the bottom end. There was no grouting (cementing) of the
DYWIDAG thread bars in to the ground (Refer to Attachment B- Photographs 5).
5.2 Observations
5.2.1 Environment Canada weather records for Crowsnest area show that the temperature at
the time of the incident was approximately 26 C with a wind speed of 20 km/h. The
location where the pole butt was located had considerable overburden consisting of
soil and rock fragments.
5.2.2 Galbraith Power (BC) Inc. personnel had previous experience in the use of the Tri-
Anchor pole mount system but Altalink L.P. was not familiar with the system.
5.2.3 There were no engineering specifications available for the temporary wooden pole
structures installed with a modified Tri-Anchor pole mount system.
5.2.4 Galbraith Power (BC) Inc. personnel at the site had determined that the terrain at the
site of the structure 29 was not solid enough to use the 0.61 meter long anchors of the
Tri-Anchor pole mount system. Instead, Galbraith Power (BC) Inc. decided to drill
1.83 meter deep holes and to use #8 DYWIDAG thread bars as anchors to the Tri-
File: F 6183257
Alberta Human Services, Occupational Health and Safety
Anchor collars.
SECTION 6.0 NARRATIVE DESCRIPTION OF THE INCIDENT
6.1 On August 17, 2011, Greely Rock drillers (Josh Veres, Bill Ethier) drilled 4 holes for
each of the two temporary poles to a depth of 1.83 meters at locations marked by
Empirica Energy Inc. personnel at the site of the structure 29. The holes were drilled
using a Tri-Anchor template. They inserted a #8 DYWIDAG thread bar into each
hole and slid Tri-Anchor sleeves over the #8 DYWIDAG thread bar.
6.2 On September 9, 2011, Galbraith Power (BC) Inc. line crew consisting of foreman
(Wayne Hanis), lineman 1 (Ron Stewart), lineman 2 (Shawn Gaudrey), lineman 3
(Darren Harvey), trade trainee (Tyler Ebenal), lineman apprentice (Evan Horkoff) and
the general foreman (Nico Geelhoed) arrived on site and installed the Tri-Anchor
modules over the #8 DYWIDAG thread bar to form the collar of the pole mount. The
temporary wooden pole was flown into the location by helicopter and lowered into
the Tri-Anchor collar. The line crew guided the pole butt into the collar and tightened
the collar. Three temporary ropes attached to the pole were connected to ground
anchors to provide stability to the pole.
6.3 The same procedure was repeated for the second pole. After the helicopter left, the
journeyman lineman 1 (Ron Stewart) climbed the poles and attached two guy wires
from each pole and connected them to ground anchors. A third guy wire, called a
“bridal” was attached to connect the two temporary poles horizontally. The three
temporary ropes attached to the pole were removed.
6.4 On September 10, 2011, the line crew (Wayne Hanis, Ron Stewart, Shawn Gaudrey,
Darren Harvey, Tyler Ebenal and Evan Horkoff) returned to the site and installed
work platforms (Baker boards) on the temporary poles. Working from the Baker
boards, the crew proceeded to remove the existing power line. They successfully
lowered the east and west conductors and removed the cross braces and rigging from
the old structure. The crew installed slings on the old poles and the temporary poles to
facilitate their removal.
6.5 After removing the bridal guy wire, they attempted to lower the centre conductor to
the ground. The conductor came down against the west temporary pole which caused
it to lean westward into the side of the mountain, partially pulling out a DYWIDAG
thread bar from ground on the east side of the pole. The line crew managed to lower
the centre conductor by rigging and pulling the conductor towards the east temporary
pole.
File: F 6183257
Alberta Human Services, Occupational Health and Safety
6.6 The crew cut the leaning west temporary pole above the Tri-Anchor attachment and
dropped it to the ground, then flew it out to the storage yard. The old lower pole was
also removed and flown away to the storage yard. The remaining guy wires on the
east temporary pole were removed.
6.7 It was observed that the 3.1 meter sling attached to the temporary pole was not long
enough to reach ground and allow for hook up to the helicopter for removal. With the
permission of the foreman (Wayne Hanis), the apprentice (Evan Horkoff) climbed the
temporary pole to connect an extension sling. He was wearing the required safety
gear and was attached to the temporary pole. When the apprentice (Evan Horkoff)
was close to the sling already attached to the temporary pole, it started to lean.
6.8 The temporary pole fell to the down side of the mountain, partially pinning the
apprentice (Evan Horkoff), under the pole. The foreman (Wayne Hanis) and Lineman
1 (Ron Stewart) immediately climbed down to the location of the apprentice to assist
him.
6.9 The foreman (Wayne Hanis) called the rescue team, the helicopter and Emergency
Medical Services (EMS). The rescue team extracted the injured worker and helped
move him into the helicopter. The helicopter airlifted the injured apprentice (Evan
Horkoff) to an EMS vehicle that was waiting on nearby Highway 3. EMS transported
the injured apprentice (Evan Horkoff) to the Blairmore hospital where he succumbed
to his injuries the same day.
SECTION 7.0 ANALYSIS
7.1 Direct Cause
7.1.1 The apprentice (Evan Horkoff) fell to the ground when a temporary wooden pole he
had climbed fell.
7.2 Contributing Factors
7.2.1 The Tri-Anchor system was not used in accordance with the manufacturer’s
specifications. The surface rock at the location did not meet the manufacturer’s
requirements.
7.2.2 The modifications to the Tri-Anchor system as used to construct a temporary
structure were not performed in accordance with specifications certified by a
professional engineer. There were no engineering specifications for the erection, use
and dismantling of the temporary pole structure.
7.2.3 The #8 DYWIDAG thread bars used as anchors were not grouted in or anchored to
the rock. There was no procedure in place to ensure that #8 DYWIDAG thread bars
were adequately anchored to the rock to support the temporary poles.
File: F 6183257
Alberta Human Services, Occupational Health and Safety
7.2.4 The line crew was not aware that the #8 DYWIDAG thread bars were not adequately
anchored to the rock. Some bolts on the top end of the modules tightened due to the
presence of bolts at the bottom end.
7.2.5 The guy wires holding the pole had been removed prior to the incident.
7.2.6 The sling attached to the pole was not long enough to reach the ground, requiring the
attachment of an extension sling.
SECTION 8.0 FOLLOW-UP/ ACTION TAKEN
8.1 Human Services, Occupational Health and Safety
8.1.1 On September 10, 2011, Occupational Health and Safety (OHS) received an incident
notification. Occupational Health and Safety Officers responded to the scene
immediately and commenced an incident investigation.
8.1.2 OHS issued an order requiring the prime contractor to conduct an incident
investigation and prepare a report.
8.1.3 OHS issued a Demand for documents related to the incident.
8.1.4 OHS issued a stop work order for work activities requiring workers to climb poles
supported by Tri-Anchor systems until the cause for the incident was determined.
8.1.5 OHS hired a consulting geotechnical engineer to evaluate the anchoring system used
at the location to secure the temporary pole.
8.2 Industry
8.2.1 On September 10, 2011 following the incident, Galbraith Power (BC) Inc. voluntarily
stopped work on the 170L power line prior to the arrival of OHS.
8.2.2 Galbraith Power (BC) Inc. stopped using the Tri-Anchor pole mount system.
8.2.3 The prime contractor conducted an incident investigation and submitted a report to
OHS.
8.2.4 The employer and prime contractor complied with all orders issued by OHS.
File: F 6183257
Alberta Human Services, Occupational Health and Safety
8.3 Additional Measures
8.3.1 When Tri-Anchors are to be utilized, the prime contractor, Altalink, L.P. required all
contractors to obtain an assessment of conditions by a professional engineer to ensure
sufficient anchoring. In addition, all contractor personnel involved in the installation,
use or removal of temporary poles and the Tri-Anchor System are required to be
trained on the procedures and manufacturer’s specifications for their installation, use
and removal.
SECTION 9.0 SIGNATURES
Original Report Signed October 15, 2014
Lead Investigator Date
Original Report Signed October 15, 2014
Reviewer Date
Original Report Signed November 17, 2014
Director Investigations Date
SECTION 10.0 ATTACHMENTS:
Attachment A - Map
Attachment B - Photographs
Attachment C - Tri-Anchor manufacturer’s specifications
Alberta Human Services, Occupational Health and Safety
GALBRAITH POWER (BC) INC. File: F-6183257
Attachment A
Map
Map – Arrow shows the location of the incident, approximately 1 km east of Blairmore, Alberta.
Alberta Human Services, Occupational Health and Safety
GALBRAITH POWER (BC) INC. File: F-6183257
Attachment B
Photograph 1 of 5
Photograph 1 – Shows the view of the incident site from Highway 3. Arrow shows the fallen
temporary pole.
Alberta Human Services, Occupational Health and Safety
GALBRAITH POWER (BC) INC. File: F-6183257
Attachment B
Photograph 2 of 5
Photograph 2 – Shows an aerial view of the incident site.
Alberta Human Services, Occupational Health and Safety
GALBRAITH POWER (BC) INC. File: F-6183257
Attachment B
Photograph 3 of 5
Photograph 3 – Shows the site of the incident.
1) Old permanent pole (west)
2) DYWIDAG thread bars on the fallen pole pulled out from the ground
3) Tri-anchor collar
4) Stump of the old permanent pole (east)
5) Butt section of the temporary pole (west)
6) Tri-anchor collar on the temporary pole (west)
1
2
3
4
5
6
Alberta Human Services, Occupational Health and Safety
GALBRAITH POWER (BC) INC. File: F-6183257
Attachment B
Photograph 4 of 5
Photograph 4 – Shows the fallen temporary pole on the side of the mountain.
Alberta Human Services, Occupational Health and Safety
GALBRAITH POWER (BC) INC. File: F-6183257
Attachment B
Photograph 5 of 5
Photograph 5 – Shows the butt section of the temporary fallen pole.
1) Pulled out #8 DYWIDAG thread bars
2) Tri-anchor collar
1
2
Attachment C
Tri-anchor manufacturer’s specifications