This will be a fast overview, mainly as a photo essay, on the bloomery iron smelt carried out at Wareham on June 14, 2014.
The prototype is Culduthel, Scotland, circa 200 - 400 AD.
The furnace is a 'slag room' type, with a clay shaft built on a withy frame, over a stone base. The general details of the layout were similar to other Late Iron Age / Viking Age furnaces built in the past. The material used was a 50 / 50 mix of dry clay and course sand.
(See the earlier post :
Scottish Dark Ages Iron Smelt )
This smelt was a test / training for the 'Turf to Tools' project being undertaken at the Scottish Sculpture Workshop over August 9 - 25, 2014.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhI2OklyBWFQs2hFLSI1JvpsUwbuSLdSvoglm4OLP7sNAOVmBZ11HVqzwJf60mYk5WNAqkx12fNbTezgtZiSS_MKea9_DGwjt7r6t4D4R6hhGsPoncSQ4Iwo8eM8uVRKr63Pix9HQ/s1600/build.jpg) |
Clay shaft being built up on a wicker frame, over a stone base chamber. |
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgE_xLmZW4bTO6mqxztqqcSPOZh92sbmdk3d-82OOgKNy6m7kMue4pEJEhXY1O77X5tQ9oa3gPF-yBkSEL4a_TzaCppRI0i2LLlJvkMtWu_AzbmqTqtnR487kEdk7DLV4sOi7fL5w/s1600/cracking.jpg) |
After drying fire - extensive cracking of the shaft (extraction point to right) |
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEifEYtg414SlxwRrI3QlPFRbF-di0HGl7-5xBH5SZMTL_7F3mN_8ATckJfoBqOl6x8dz_DRC8y5b0c8TZ28C83enEG2Zmzr2js0VrXiZVZozwNc3lz4yUCEoM-AbvEESxxpeAa4eA/s1600/set-up.jpg) |
Equipment set up, at pre-heat phase. |
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgPVp_yfDQLVVGKPfXpKeU1D29YSJKaobsCGkfU7SB5c2T5KFlCzBIx37OiqOAYmbHa573YMCOM-ntZYPdpmChEeIB693UBid3imwqnPjZ-Bl_EE-pMtvYNVQC1mFC5ZeKg0cL_fA/s1600/analog.jpg) |
Adding the DD-SSW1 analog |
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiNoZjHz_V3aM7SpymXSldAW9MByXAPBAy9co1U80bgNj-6JeRFVsR_uL62SQ4SCn7d2F03AU8s4XCJIXElz9TQnp1vzAK_iPbBMBg1TlzBowM3WLRV1dBiYJPOCojiOy7oFkk71A/s1600/extracted.jpg) |
Bloom mass at initial extraction. Bottom pull was intended, but top extraction was required. |
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgtfVraqBNqMIIH9tMP6MRpsA3ePTQ9-FZL9L15R42Y5MZzn054lEV-N7Qry449EYjMdm59vf_jc5Afs5Gt8cKLPvvALXAseA5NNkFV22lV5uPYmozptIUP21Ew6VCzrflssQd-Ig/s1600/cutting.jpg) |
After two initial compaction heats, an attempt to cut the bloom. |
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgMhWiczogHzkkH-bR8q1N1LsR5dNzmlAjG7fZo42SbTC1OUsgTbNaVb9mEMbsBrcVuIGW7cc0AtpjMdh6yJrKsqyZeOx-jVlryxtvG8HWbXiFvk7MgslJnGCwpSLqoirJ3KUs_TA/s1600/bloom.jpg) |
Final Bloom : 5.2 kg (from 28.3 kg dry ore = 18% yield) |
The next day, the bloom was re-heated and compacted using the hydraulic press. After cutting to quarters, the interior surface was spark tested. The observation suggests roughly .6 -.7 carbon content, a good blade making material. (!)
The following will be of more interest to the archaeologicallly inclined:
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjVA3OtbSlKjq-u5WwePS1nyyB8pf0t0de5gRNZFjvaGsbv3eC0YwlVn-YJHVaVe0pcswpKuNkE-LRnJDsZwv-6yP0SYlrP5tPE92qD82oUhkvBcfzFmbBd0I5Ccr5GhnDp_DI33g/s1600/furnace-remains.jpg) |
The overall remains from the smelt around the furnace. |
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhTjL4W6BvOVzQDkBO58YFVvWU1-DoCrp06Y6Mtc14Za7EE0GBp4j0JXEADmlKDRxGAwo9nZuIwMTwT-JVCBFFgizQdmU40XA_ZVH8N-gzVVqqXZX_yuHlXa9KVS7jRfFSXhKpF8A/s1600/wall-remains.jpg) |
Broken pieces of the furnace, clearly showing the imprint of the wicker interior frame. |
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgWFMkFZO6IWMj35AimczY7azVD97K6bRKPjrbRLixFziP6mA0TBbCYtKC3clIu5fB6S-F6k8mFiI6xtvSHZHVET4PZRynx7UMKVDgfQgkJLhGjQj3o9prf0doYYWNKh0HxyBAOEg/s1600/slag-in-place.jpg) |
Furnace opened along the major cracks, showing the slag bowl in place below the tuyere entrance. |
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjXqwL51TPkbr1OCIoisdfI3SELvEcaKL9iUGiP8-IWDijMLUmF4zObos1gSPpO0ppH_0GuVOsSK2lkcl2CAzR6KKZqZed_R7xPpSCZXlh4Rv8_zMSMtYIq1P9vhUMn3o7Ere74DQ/s1600/slag-bowl.jpg) |
Main slag bowl removed as two pieces. The tuyere was to the left. |
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhxIzoGLi9xn81p6fivEIjfwxRW2NMGYTcoFlhDDITvUKbx3TE22s5hdRbiyceLYszg6vtwOzUB7RbhtAPiMqusht4fVfw1W3zE3BWEh05u1FuJvS2PNuEdRv6iytlpl34mHwwCPA/s1600/base-remains.jpg) |
Cleaned surface of the rock base. Tuyere was to the top. |
There will be a fuller report to come on making a comparison between the results here, and the remains seen in the archaeology from Culduthel.
Some General Conclusions:
- Some modifications to the layout and construction of the furnace may be necessary to :
- avoid cracking
- conform more closely to the slag pattern at Culduthel
- The analog used proved quite successful, even if the yield was a bit low.
- The general progress of the smelt followed the expected pattern.
- A better system needs to be established for re-heating the bloom for consollodation.
With thanks to the working team:
Kelly, Ron, Heather, Rodger, Neil, Richard.
No comments:
Post a Comment