wefalck

That makes perfect sense 👍🏻

As in the case of purchasing any kind of machine tool, it is useful to make a list of fundamental specification and capabilities needed: - Which are the maximum dimensions of parts I want to produce? - What is the maximum thickness of materials I want to work with? - What kind of materials do I want to work with? - What sort of operations I want to do, i.e. cutting out 2d-objects or sculpting 3d-objects (2-axis router vs. 3-axis milling machine) - What is the spatial resolution needed? - Do my objects have have to have sharp corners or can I live with or hand-treat rounded corners? Then also a list of possible constraints is helpful: - Do I have the surface space to permanently accomodate the machine ? (moving it around may cause alignment issues) - Do I have the possibility to vent out fumes? - Do I have connections for cooling water? (needed for some types of lasers) - When do I want to work with it re. nuisance due to noise produced by routers - How can I manage dust? 'Sculpting' with a laser in principle is possible by modulating the power and/or the lengths of pulses and the number of repeated passes. However, it always will result in charred surfaces and removing the charred wood form small intricate parts can be difficult, particularly when one wants to have the 'real' wood surface in the end. On the other hand, the laser works 'contact-less', which is particularly useful for very small and delicate parts.

Never heard the term 'guest-rope' before, but seems to make sense for something a boat crew could hold onto while coming alongside. However, in such a case, I would have expected the hope to be running more or less horizontally, while on virtually all the pictures one end is tied up to the bottle-screws or thereabouts. I know that yachts-people sometimes jump ashore and grab the shrouds to pull their boat towards the quay, but I am not so sure that would work for a 150 ton schooner. Otherwise the 'guest-rope' could help in such endeavour. However, I would rather expect one man to jump ashore and another throwing the mooring line to him, with which the ship could be coerced more safely towards the quay. A puzzle ...

He doesn't take a breath before starting a new project ... Good thing that this is a historic ship, otherwise one would wonder, whether it would stay afloat long enough to complete the model 😲

The darker colour shows that the linesee oil penetrates deeper, while the water-based sealer stays more on the surface. The oil penetrates into the pores and acts as a kind light conduit deeper into the wood, similar to fibre optics, so less light is reflected and hence the wood appears darker. Water-based sealers do not penetrate so well, as wood is naturally somewhat hydrophobic, even wood that does not contain much resin, like cherry. That's why I am still using solvent-based sealers ... as long as one can get them.

Well, I think this thread is interesting (apart from the fact that a topsail-schooner is on my project list), because it shows the wide variety of possible arrangements. I may have said this before: we tend to be too framed by naval practices and rules, and by yachting 'rules', which in turn had been strongly influenced by naval costums. In the merchant navy anything that worked was permitted. If it didn't work, it silently disappeared or, when it involved an accident, it may have been branded as bad practice in court, leading to the master loosing his patent. Also, when we see a particular arrangement in historical photographs, we don't know, whether this was an arrangement of the moment or a permanent feature. On the other hand, too much variation and to many fancy arrangements would have been probably counterproductive in an industry, where the workforce often changed frequently. Sailors on larger ships typically stayed only for one roundtrip. On coastal vessels they may have stayed for years. The point is that a sailor coming on board newly will have to 'learn the ropes' of this particular ship and may grab the wrong one in situations of stress. So it would be good practice to have not too many differences from ship to ship.

Nice to see an Omani craft being built here. Since a couple of visits in to Oman in 1989/90 (I had a friend working there in the oil industry, there were not tourist visas yet), I got interested in their craft. On the design of the stern: on their way around Africa and further to India, the Portugues arrived in Oman in the later 16th century and established a base there. The forts in Muscat were originally built by them. The local shipbuilders began to copy the design of the European hulls then. They never adopted the European square rigs though, as the settee-sail (which is four-sided, as opposed to the three-side latin sail) was much better suited to the seasonal trade driven by the monsoon. Typically an annual round-trip was made from Oman down to East Africa/Zanzibar, then across to India and back to Oman. African slaves were transported from Zanzibar a major trading hub for them directly to Oman. Wood was a major commodity imported from India, as there is virtually no boatbuilding wood available in Oman. While big trading dhows are now extinct, small trading and fishing dhows are still being built, but not in Oman anymore (though there is still a yard in Sur I think), only in modern Tanzania (incl. Zanzibar mainly) and Kenya. Here are some photographs of dhows and dhow-building in Dar-es-Salaam and Zanzibar: https://www.maritima-et-mechanika.org/maritime/tanzania/tanzania.html. For those interested to dive deeper into the matter, I have some reading suggestions: Dhow Bibliography Agius, D.A., Cooper, J.P., Zazzaro, C. (2014): The Maritime Heritage of Yemen: A Focus on Traditional Wooden ‘Dhows’.- In: Agius, D.A., Gambin, T., Trakadas, A [Eds] Ships, Saints and Sealore: Cultural Heritage and Ethnography of the Mediterranean and the Red Sea: 143-157, Oxford (Archaeopress). Agius, D.A., Cooper, J.P., Zazzaro, C., Jansen van Rensburg, J. (2014): The Dhow’s Last Redoubt? Vestiges of Wooden Boatbuilding Tradition in Yemen.- Proc. Seminar Arabian Stud., 44: 71-84. ANONYM (1979): Oman, a Seafaring Nation.- 196 p., Sultanate of Oman (Min. of Information and Culture). ARGYLE, E.W. (1954): The Ancient Dhow.- Seabreeze, New Ser., XVIII: 262-5. LE BARON BOWEN, R. (1949): Arab Dhows of Eastern Arabia.- Rehoboth, Mass. Carvalho, F. da Piedade (2014): Os Dhow do Zanzibar: A técnica de construção de uma antiga embarcação de origem árabe e o seu papel socioeconómico na actualidade.- Cadernos de Estudos Africanos, 27(6): 149-170. DOI: 10.4000/cea.1535. CHETHAM, M. (1950): Dhows in East Africa.- Country Life, CVIII: 1803-7. De Leeuwe, R. (2004): Seascape and Sailing Ships of the Swahili Shores.- MA Thesis: 123 p., Leiden (University of Leiden). De Leeuwe, R. (2005): Constructing Sailing Ships on the Swahili Shores.- Azania: Archaeological Research in Africa, 40(1): 107-113. De Leeuwe, R. (2006): Swahili Ships in Oceanic Perspective.- Sails of History: Citizens of the Sea, ZIFF Journal No. 3: 45-52, http://www.swahiliweb.net/ziff_journal_3_files/ziff2006-07.pdfK Ennion, H. (1963): Along the Shores of the Gulf of Oman.- Country Life, CXXXIII: 1265-6. ‘FULAHIN’ (1928): Coasting East Africa by Dhow.- Blue Peter, V: 449-52. FALCK, W.E. (2013): Boote und Bootsbau in Tansania, Teil 1: Dauen und Einbäume in Dar-es-Salaam.- Das Logbuch, 49(1): 27-30, Köln (AK Historischer Schiffbau). FALCK, W.E. (2013): Boote und Bootsbau in Tansania, Teil 2: Bootsbau auf Sansibar.- Das Logbuch, 49(2): 62-65, Köln (AK Historischer Schiffbau). FALCK, W.E. (2014): Boats and Boatbuilding in Tanzania (Dar-es-Salaam and Sansibar).- Int. J. Nautical Archaeology, 43(1): 162–173. GILBERT, E.O. (1997): The Zanzibar Dhow Trade. An Informal Economy on the East African Coast, 1860-1964.- PhD Dissertation: 340 p., Boston (Boston University). HAWKINS, C.W. (1977): The Dhow – an illustrated history of the Dhow and its World.- 143 p., Lymington (Nautical Publishing Co.). HORNELL, J. (1941): The sea-going mtepe and dau of the Lamu Archipelago.- The Mariner’s Mirror, 27: 54-68. HOWARTH, D. (1977): Dhows.- 159 p., London (Quartet Books Ltd.). Issa, A.A. (2006): Dhows and Epidemics in the Indian Ocean Ports.- Sails of History: Citizens of the Sea, ZIFF Journal No. 3: 63-70, http://www.swahiliweb.net/ziff_journal_3_files/ ziff2006-09.pdf JEWELL, J.H.A. (19762😞 Dhows at Mombasa.- 103 p., Nairobi (East African Publ. Ho.). MONDFELD, W. (1979): Die Arabische Dau.- 93 p., Bielefeld (Verlag Delius, Klasing & Co.). MOORE, Sir A. (1940): Notes on Dhows.- The Mariner’s Mirror, 26(2): 205-13. SASSOON, C. (1970): The Dhows of Dar es Salaam.- Tanzania Notes and Records, 71:185-199. SHERIFF, A. (2010): Dhow Cultures of the Indian Ocean. Cosmopolitanism, Commerce and Islam.- XV+351 p., (). SPARKS, W. (1909/10): A Muscat Dhow.- Yachting Monthly, VIII: 263. SULIVAN, G.L. (1873): Dhow Chasing in Zanzibar Waters and on the Eastern Coast of Africa. Narrative of Five Years’ Experiences in the Suppression of the Slave Trade.- X+453 p. VILLIERS, A.J. (1940): Sons of Sindbad – An Account of Sailing with the Arabs in their Dhows.- Villiers, A.J. (1954): Passage in a Red Sea Dhow.- The Mariner’s Mirror, 40: 171-82. Villiers, A.J. (1961): Vanishing Ships – Arab Dhows.- British Petroleum Shield, 5: 6-8. VOSMER, T. (1993): The Omani Dhow Recording Project: Sultanate of Oman.- Indian Ocean Review, 6(2): 18–21, Perth. VOSMER, T. (1997): Indigenous Fishing Craft of Oman.- Internat. J. Nautical Archaeol., 26(3): 217-235. VOSMER, T.A., MARGARIT, R.A., TILLEY, A.F. (1992): A Survey of Traditional Vessels of the Sultanate of Oman. The Omani Dhow Recording Project. Field Reasearch 1992.- Department of Maritime Archaeology, Western Australian Maritime Museum, Report No. 69: 80 p. WEISMANN, N. (1994): Der Beden-Safar – Eine Rekonstruktion nach Unterlagen von Admiral Pâris.- Das Logbuch, 30(3): 160-67. WEISMANN, N. (1995): Ein Fischer-Beden in Qurm (Sultanat Oman).- Das Logbuch, 31(4): 175-82. WEISMANN, N. (1996): Der Beden-Seyad – Ein Fischerboot des Omans im letzten Jahrhundert.- Das Logbuch, 32(4): 175-80. WEISMANN, N. (1998): The Cargo-Beden Al-Khammam.- Internat. J. Nautical Archaeol., 27(3):237-257. WEISMANN, N., STAPLES, E., GHIDONI, A., VOSMER, T., DZIAMSKI, P., HAAR, L. (2014): The Battīl and Zārūqah of Musandam, Oman.- Int. J. Nautical Archaeol., 43(2): 413–435. WIEBECK, E., WINKLER, H. (2000): Segler im Monsun. Die Dau am Indischen Ozean.- 130 p., Rostock (Neuer Hochschulschriftenverlag). WISEMAN, W.F (1994): Modeling a Ninth-Century Arab Dhow.- Nautical Res. J., 40: 5-17. YA’QUB, Y. Al-Hiji (2001): The Art of Dhow-building in Kuwait.- 164 p., London (The London Centre of Arab Studies). Tim Vosmer and Norbert Weismann are probably at the moment the most knowledgeable persons on Omani dhows.

We keep fingers crossed then !

Yes, it looks more railway tunnel-like and not just like a hole in the mountain 👍🏻

This all begs the question: What next?

Just out of cultural curiosity: how did the 'doctor's buggy' got its name? I now that in 'Westerns' doctors are often portrayed as driving one, but I am sure there would be more numerous people having/driving one. Nice job on the model btw.

As always, it is probably a question of scale. I used in 1:60 scale some wooly knitting thread, twisted it tight and then soaked it in varnish. Once dry is was roughend with sandpaper and then with a thin needle the respective rigging line was threaded through. Looked convincing enough to me. Sorry I don't have a picture to hand at the moment.

We lived for a couple of years near a branch-line during the last days of steam back in later 1960s Germany and used to play around the embankments. One day we had to alarm the adults as indeed some shrubs/weeds had caught fire after a steam-train passed. It seems that this, however, was less likely with coal-fired engines, while wood- (or peat-fired, as was the case for a period in Bavaria) always had those bulbous spark-arrester chimneys.

On harder woods I use single-sides razorblades as scraper (the ones that have a reinforced back). However, getting things smooth around knots may indeed be difficult. What would help is to treat the surface with a sanding-sealer. That would harden the soft fibres around the knot, making sanding/scraping easier. Another good way to smooth the surface is the use of different grades of steel-wool in between coates of sanding-sealer. However, there is no point then applying lineseed-oil, as it would not penetrate the wood treated with sanding-sealer. There may not need to be a need for further treatment, as the wood treated with e.g. cellulose-based sanding-sealer and rubbed down with fine steelwool takes on a nice satin shine.

Very nice indeed 👍🏻 Did you sculpt the figures yourself? They are very well animated.

Use Paasch‘s ‚From Keel to Truck‘ and forget about GoogleTranslator …

Well, the 'hog-chains' are there to prevent exactly that, the 'hogging' of the boat. It has the same function as the girders/trusses on a bridge above the way. Shallow hulls without (external) keel may not have sufficient strength against bending/hogging, so they need these trusses in the same way a girder-bridge needs them. These trusses are not necessarily chains, but could be iron rods or connected wooden beams. A girder structure of wooden beams could be hidden in the constructional arrangements of superstructure without being so obvious as in the old-time river-boats. Extending the trusses/hog-chains beyond the pivotal pole of the derrick, however, could limit its range of movement. So I would doubt that in a real case they would have been extended further, though from a mechanical point this would be advantageous.

Well, real life's necessities come in our modelling way - even as pensioners it seems. Good that you can see light at the end of the tunnel. Builders always take longer than they originally claim they would. I have something like that lurking behind the horizon as well ...

Sorry for having tread this loose ... you could run a pair of chains (or solid bar stays) from the forward end of the canopy over the boiler further forward, say towards a point at the hull left and right of the mast.

This is indeed how the trusses are led on riverboats and other shallow boats that do not have a strong keel as backbone. Incidentally, such trusses already occur on ancient Egyptian boats ...

Yep, installing chains properly tensioned is not so trivial, as they do not stretch. On the other hand, in full-scale they have the same problem and one would normally have a turnbuckle there. Looking at the design, I was wondering, whether there shouldn't be another set of chains on the other side of the deckhouse - its structure alone would not be able to balance the strain from the sponsons, I think.

I think, I have seen representations where the forecourse on the lee-side is brailed up, as it would blanket the foresails, but here it is clearly a triangular sail set (flying) to windward. One thing I noticed is that we tend too framed by navy rules and regulations, where everything was supposed to be done 'by the book'. In the merchant navy the master basically could do whatever he saw fit and if it worked, the better. If something went wrong, however, he may have had to explain himself in front of a court. So in practice, one probably saw all sorts of strange arrangements.

There is a lot of hype about AI and no one usually knows what it really means 🤪 I am using ChatGPT quite a bit in work to get an overview over a subject that I don't know (very well) to give me directions where to dig deeper. It gives the sources now, so one can verify them. The subject coverage seems to be quite variable still, with niche subjects, like ours, being hit-and-miss - as more people ask the right question the system learns and begins to return better answers. ChatGPT becomes really a challenge for our university teaching - while unreferenced Google results were relatively easily to detect (by a Google search 😉), this has become now more difficult. I changed my tactics and tell my student to use it explicitly 😈. When I first plugged my exam questions into ChatGPT, I was flabbergasted, that it came up with the correct answers, even for things on which the students normally failed ... One needs to cascade through various rounds of refinement when posing questions to either Google or ChatGPT in order to arrive at more probably results. Nevertheless, I don't use it very often for our subject area (yet). Back again to LULA now ...

Sorry, I don't want to dilute the thread, but I am curious, when a broom would be a 'push-broom', rather than just an ordinary wide broom? Below is an image of Berlin street-sweeps from around 1910, who seem to push fairly wide brooms:

I have seen triangular forecourses, but set in the middle of the yard, with the foot pivoting on an eyebolt in the deck. I think in German it is called 'Faulenzer' = idler. It was used on courses werde frequent gybing was required, as it involves less work. Haven't seen such half-forecourse, however, before.