1. Tree-rings, timbers and trees:
a dendrochronological survey on the Doel ships
Kristof Haneca
April 25, 2013

2. 99,9 % oak
Wood identification
ship timbers: oak (Quercus robur/Q. petraea)
1 treenail: beech (Fagus sylvatica)
fenders:
alder (Alnus sp.)
“the softer hardwood”
alder European oak
Density 12% (kg/m³) 490-640 500-970
Density 'green' (kg/m³) 680-1000 900-1200
Hardness (Janka, N/mm³) 33-38 50-66

3. Tree-rings, timbers & trees
• 129 new +
18 RING
• incl. 6 repairs
147 tree-ring
series
• 63 dated
• 38 undated
101 timbers
• 52 dated
• 38 undated
90 trees
• 4 dated
• 2 undated
6 repairs
tBP ~ 10
PV% ~ 85
DOEL 1

4. All dated timbers, DOEL 1

5. hull planks vs. framing timbers, DOEL 1

6. Repairs: average of 3, DOEL 1

7. Felling date Doel 1: 1325/26 AD
1325 AD

8. Date of repair (along Southern Baltic coast)
End date 1320
No sapwood !
Sapwood estimate 7-26 (94,5% CI)
Average n°: 19
Felling date certainly after 1327 AD
Assuming HW/SW: 1339 AD
> 13 years after construction

9. Provenance DOEL 2
Felling date (95,4% CI): between 1326 and 1340 AD

10. DOEL 1, strakes A-D
symmetrical layout
(same colour = planks from the same tree)

11. Conclusions
Unique dataset
> 162 tree-ring series from 2 ships
Dating and provenance (Doel 1 vs. Doel 2)
More or less contemporaneous
Different provenance
Repairs Doel 1 same origin as ship timbers Doel 2
Repairs!
Provide most information
Date of repair
Location of repair <> construction site
Doel 1 >13 years “in action”
…
Wood conversion and shipbuilding
Symmetrical layout of bottom strakes
Keelplank: stockpile or ponding?

12. Doel 3: dendro DIY
Target timbers with sapwood or bark
Both framing timbers and planks
~20 samples (min!)
Concentrate on repairs
Research questions
Wood conversion
Symmetrical layout?
Also analyse timbers with short TRS
Stockpile or watering of some crucial structural timbers?