Steam locomotive 924 insulation removal

Edwin from Global Asbestos Contractors checks verifies the entry door seal on the containment structure.

In early August, remediation work began working with Global Asbestos Abatement, a
licensed asbestos contractor.  By partnering
with this firm, valuable advice and experience was available to the team,
but perhaps more importantly the necessary equipment to complete the job safely and effectively.
 

A double-wall containment structure was built over locomotive 924.

Over the course of three days, the mandated double wall containment was
constructed of polyethylene sheeting, and taped so as to be air tight to a
minimum of -.018 inches of mercury with HEPA negative air machines running.
 A three stage decontamination chamber was built and attached to the front of the
enclosure, and pre-abatement samples taken so as to demonstrate a clean and
safe working environment, and provide comparison for the post abatement
samples.  All work conducted in the enclosure was accomplished using full
face respirators with external supplied air, full coverage Tyvek suits, as well as
appropriate personal protective gear such as hearing protection, gloves, etc.  

Insulation is sprayed with water prior to removal to reduce the likelihood that fibers will be introduced to the atmosphere.

The
removal of the jacket and insulation took approximately a day and a half to
remove and safely bag for disposal.  Although the original jacket was in
very poor shape, the reason for involving trained museum professionals in the
actual remediation was highlighted in the data collected that will be useful as
rehabilitation of the locomotive continues.  Hardware such as boiler band
brackets, washout plug ferrules, and other assorted hardware was removed,
cleaned and saved for reuse.  In addition, various samples of trim
treatments, riveting of jacket panels, etc were also saved, and will allow the
team to match the original methods of construction as closely as possible.
 Illustrating how this benefits the Museum was a discovery made on the inner surface of
the jacket located just beneath the hydrostatic lubricator bracket: an
uncorroded patch of the original American Iron boiler jacket surface.
 Samples such as these are rare because the oxide finish of both Russian and
American Iron was extremely prone to corrosion and loss if not kept continuously
oiled.  Curator Pappas noted the extremely oil soaked appearance of the
jacket and insulation in this area due to frequent overfilling and leakage of
the hydrostat over many decades of service, and was particularly mindful of the
potential presence of an unadulterated sample.  

Clean boiler!

Following the removal of the material, the arduous process of
cleaning all surfaces of the locomotive and containment began.  The next
three days were required to assure the successful completion of the job.
 The surface of the boiler was rough due to surface corrosion, and
provided an ideal surface for asbestos fibers to be trapped and potentially
endanger individuals working on the locomotive in the future.  To avoid
this possibility, all flaky rust was removed with a chipping hammer and wire
brushed while moistened to clean the surface.  More aggressive methods
such as needle gunning and wire wheeling are usually not employed as these can
raise the concentration of fibers in the containment to unsafe levels, even
with full face mask protection.  After this step, all surfaces of the
locomotive and containment were vacuumed using a HEPA vaccum cleaner, and all
debris double bagged and removed from the containment.  Although this may
sound like a relatively simple matter, the work in full protective gear on a
hot summer day can be exhausting!

After the insulation was double bagged and removed, the enclosure room was cleaned and locked down. An air sample was collected during a two hour interval to verify that there was no airborne fibers prior to removal of the containment.

Once everything was cleaned, a final wash down with water was
conducted over every surface.  The water was then collected below the
engine, and pumped through approved water filters to remove any asbestos micro
fibers.  All of the secondary inner walls of the containment were sprayed
with a fixative called Lockdown, taken down, rolled, and double bagged for
removal.  Then all primary surfaces were also sprayed with lockdown and
clearance air samples taken.  This last step is critical to assure the
safety of anyone in the shop, as once the containment is breached, any
contamination will remain.  After the samples were examined by a third
party local laboratory, air quality was found to be ideal, with the lowest
presence of asbestos recordable!