Improving collections care

Stewardship of a massive collection like the Northwest Railway Museum’s can be daunting.  A trained curator can quickly see there are issues with storage conditions, damaged artifacts, and security. Heat, light, humidity and too few restrictions on collections access are the usual culprits, but they do have to be identified and assessed before they can be mitigated. So what to do?

Cristy L. highlights one of the

new dehumidifiers in the

periodical and drawing

storage area.

For starters, solving collections challenges is a long term process – there are no quick fixes in this field.  In 2006 the Museum hired Randy Silverman, preservation librarian at the University of Utah’s Marriot Library in Salt Lake City, to conduct an assessment and write a preservation needs report.  That project, funded with a grant from the National Endowment for the Humanities, has helped guide a long term strategy to improve collections care, primarily through improved collections storage.


The latest implementations of the Silverman report's recommendations - thanks to a 4Culture Collections Care Grant - are the acquisition of three dehumidifiers and a special museum vacuum.

Environmental monitoring devices were installed in collections areas in 2010 and 2011.  With nearly a year of data, collections staff were able to identify areas where environmental conditions were presenting the greatest threats to the collection.  Three areas were found to have humidity that was unacceptably high on a consistent basis.  The collections care grant has allowed the purchase of three modest-size dehumidifiers that are being used to reduce humidity and improve the storage environment where small objects, periodicals and drawings are stored.

Cristy L. demonstrates the Nilfisk HEPA

variable speed vacuum on a wood crate.

Cleanliness is next to . . . well, you know the saying, and it may as well have been written for museum curators.  “Dirt” threatens museum collections, whether it be in the form of mold, dust, rodent droppings, or just plain sand.  Long term preservation needs demand that artifacts be clean and the environment that they are stored in be just as clean.

A museum vacuum has variable speed to allow control over the amount of suction, and a HEPA filtration system so that hazardous substances – such as mold or Hantavirus – are not sucked up and transmitted around the room.  So a Nilfisk model GM 80 vacuum with a museum kit has been purchased with the collections care grant proceeds.  The museum kit provides a HEPA filter, variable speed to control suction, and special attachments to get into unusual spaces.

So thanks to a 4Culture collections care grant, the Northwest Railway Museum is able to make additional improvements in collections storage conditions.  This is helping ensure the Museum’s collections will survive long into the future.

Aarrgh!

Avast me hearties:  the Snoqualmie Railroad Days committee is proud to announce the return of the SeaFair Pirates! They’re back, matey!

The SeaFair Pirates will sail inland to grace our town with their piratical presence at our community festival, Snoqualmie Railroad Days. Watch for them on Saturday in the Grand Parade. And you better watch out for those rascally pirates all afternoon too! See you at Snoqualmie Railroad Days.

 

Come join in the fun in Snoqualmie, Washington, August 17-19, 2012! www.railroaddays.com

Terne over a new roof

The original Terne roof was applied in

1898.  Pin holes, loss of coating and

breaches in the membrane left few

options for the rehabilitation.

The roof on a century-old railcar is more than just something to keep the rain out; it is a distinguishing feature.  On chapel car 5 Messenger of Peace, the roof is particularly important for what it was made of: Terne metal.  The vast majority of 19^th and early 20^th Century rail passenger cars had a canvas roof supported by a wooden deck.  The chapel car was built with a 28 gauge Terne sheet metal roof supported by a wooden deck.  It debuted in its natural state and over a short period of time oxidized to a pleasant pewter-like appearance.  In later years as the roof began to show its age, it was coated with paint and other materials to seal leaks.

Orignal Terne sheet metal produced by

Piqua in 1898.  The pewter-like
appearance is oxidation accelerated
by air pollution.  The seams were
sealed with lead solder.

Terne metal has been around for more than 200 years and in its earliest form was sheets of wrought iron coated with an alloy of tin and lead.  Thomas Jefferson’s Monticello was roofed with Terne metal at his request, and other important 19^th Century structures that were built to last also received the same treatment.  As technology improved, Terne roofing was offered as light sheet metal with its corrosion-resistant coating on both sides.  Light-weight Terne roofing could be used in a variety of lighter constructs – such as a railcar roof.

Original sheet metal roof was carefully

torn up to  allow depair of the deck.
The "holes" behind Gary were for the
kerosene lamp chimneys.

Chapel car 5 was built with a traditional Terne-coated 28 gauge carbon steel roof.  The light gauge sheets performed for more than 100 years but by the time the car arrived at the Museum, the sheets were heavily compromised with pin holes.  Complicating how this would be mitigated was the unknown condition of the underlying decking: the only way to inspect and repair was to remove the metal sheets.  It was not practicable to remove the original sheets and reuse them.  And the Museum's concern was justified: several areas of previously undetected deterioration were discovered as the original Terne metal was removed.  The ends hoods in particular had issues and new "green" white oak lath was steamed and applied to the damaged areas to rehabilitate them as new. 

New panels on the upper deck.  Metal will be kept in its natural

state in keeping with the original treatment.

A team of two sheet metal specialists

applied the new Terne II sheets.  The

center panel of the upper deck slid

over the two side panels.

So what is the Terne coating?  Originally it was an alloy of approximately 79% lead and 19% tin.  So why tin?  Tin allows the molten lead to ”stick” to the carbon steel, which it ordinarily would not.  The other 2% of the alloy is additives such as antimony to adjust characteristics such as melting point.  Today, a concern over lead in the environment has evolved the product into an alloy of zinc and tin, which is now known as Terne II and is manufactured by Follansbee. Seams of Terne II sealed with tin solder. 

The hoods on the ends of the roof

were particularly challenging.

The new Terne II metal was available to the Museum in a coil steel format.  So large coils were purchased, sheared by sheet metal specialists, and each edge bent to 90 degrees.  Individual sections of roofing are connected to each adjacent panel by folding the edge of the panel over the edge of the next panel and rolling it smooth.  The seam was soldered with tin to complete the seal; work was performed by Trinity Sheet Metal of Granite Falls, WA.  In all, more than 1,800 linear feet of soldering was required to complete the roof.  The new roof – as with the original – will be left uncoated and untreated.  Over time it will oxidize to a pewter-like patina, though ironically because of cleaner air today this process will take considerably longer than it would have in 1898.

The completed roof is striking and a is

an appearance not seen for generations.

Work was completed in May and substantially completed the roof area of the chapel car.  Special thanks to major funders including the National Trust for Historic Preservation's Partners in Preservation (funding by the American Express Foundation), Save America's Treasures, 4Culture, and the Washington State Heritage Capital Projects Fund administered by the Washington State Historical Society.