hutchins_appa

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Memorandum

Date: January 25, 2006

To: Sean James, P.E.
       Project Manager
       Hoyle, Tanner & Associates
       150 Dow Street
       Manchester, NH 03101

From: Doug Gardner
           Professor of Wood Science
           AEWC Center

Subject Identification of 15 bridge timber wood samples from Bath Village Covered Bridge, E. Fairfield Covered Bridge and Hectorville Covered Bridge.

Following are my findings relative to the identification of the bridge timber wood species samples you sent to me on January 20,2006. I relied on my background in wood identification, and the Key to Gross Identification found in the Textbook of Wood Technology, 4th Edition by Panshin and De Zeeuw (ISBN 0-07-048441-4) in making my evaluations. Identification of the wood samples was made using a 10x hand lens.

Samples Identified
A summary of the wood species identified are listed in Table 1 along with comments related to the nature of the samples. More details about each sample are described below.

Table 1. Summary of wood species identified comprising wooden bride members

1. Hutchins C B Deck: Eastern Hemlock (Tsuga canadensis): wood tended to be brittle and exhibited an abrupt transition from earlywood to latewood in the growth increments.
2. Hutchins C B Chord: Eastern Hemlock (Tsuga canadensis): wood tended to be brittle and exhibited an abrupt transition from earlywood to latewood in the growth increments. Sample also exhibited signs of cubical brown rot wood decay.
3. Hutchins C B Trunnel: Hard Maple (Acer saccharinum): wood was diffuse porous hardwood. Outer margin of growth ring was dark brown in color. Wood had some signs of insect attack (holes 1/16th inch in diameter). Possibly powder post beetle attack.
4. Hutchins C B Lattice Spruce (Picea spp.). wood yellowish-white-brown and contains resin canals, exhibits a gradual transition between the earlywood and latewood in the growth increment.
5. East Fairfield C B Floor Beam: Either Eastern Hemlock (Tsuga canadensis) or Fir (Abies spp.): wood did not contain resin canals and the transition from earlywood to latewood tended to be semi abrupt which is characteristic of both species.
6. East Fairfield C B Deck: Eastern Hemlock (Tsuga canadensis): wood tended to be brittle and exhibited an abrupt transition from earlywood to latewood in the growth increments.
7. East Fairfield C B Rafter: Either Spruce (Picea spp.) or Fir (Abies spp.): the slow growth of this sample (greater than 40 rings per 12 inch) precluded positive identification. The transition from earlywood to latewood appeared to be gradual and this is a characteristic of both species.
8. East Fairfield C B Chord: Spruce (Picea spp.). wood yellowish-white-brown and contains resin canals, exhibits a gradual transition between the earlywood and latewood in the growth increment.
9. East Fairfield C B Stringer: Eastern Hemlock (Tsuga canadensis): wood tended to be brittle and exhibited an abrupt transition from earlywood to latewood in the growth increments.
10. Bath Village Bridge -Old Floor Beam: Eastern Hemlock (Tsuga canadensis): wood tended to be brittle and exhibited an abrupt transition from earlywood to latewood in the growth increments.
11. Bath Village Bridge - Diagonal: Spruce (Picea spp.). wood contains resin canals, exhibits a gradual transition between the earlywood and latewood in the growth increment. Sample was treated with creosote.
12. Bath Village Bridge - Deck: Spruce (Picea spp.). wood yellowish-white-brown and contains resin canals, exhibits a gradual transition between the earlywood and latewood in the growth increment.
13. Bath Village Bridge - Chord: Either Spruce (Picea spp.) or Fir (Abies spp.): This sample was creosote treated and the small sample size precluded positive identification. The transition from earlywood to latewood appeared to be gradual and this is a characteristic of both species.
14. Bath Village Bridge - Trunnel: White Oak (Quercus spp.): Ring porous hardwood with the earlywood vessels containing tyloses.
15. Bath Village Bridge - New Floor Beam: Most likely Eastern Hemlock (Tsuga canadensis): wood tended to be brittle and exhibited an abrupt transition from earlywood to latewood in the growth increments. This sample was completely saturated with creosote which precluded positive identification.

My consulting fee is $50 per sample, so the cost for this wood sample identification is $750.00. Payment can be made to

            Douglas J. Gardner
            484 Day Road Brewer,
            ME 04412

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