Saturday, March 14, 2015

15 March 2015 - Project Update

So what's been happening since we have last spoke..? I'll try and fill in the gaps the best I can.
  • Boiler Inspection
    • Over this period an extensive boiler inspection was carried out on the vessel, some of the tests carried out are listed below;
      • Firebox side and crown stays were checked for any signs of fractures and if they were broken.
      • The water space area's were visually inspected, in the area's that could not be seen such as the water space between the inner and outer wrappers of the firebox, a borescope camera was used.  
      • Fluorescent penetrant inspection (FPI) was carried out in the firebox on the firebox inner wrapper, the throat plate and on the tube plate. FPI is a type of dye penetrant in which a fluorescent dye is applied to the surface of a non-porous material in order to detect defects that may compromise the integrity or quality of the part in question.
      • Numerous area's were thickness tested using ultrasonic testing equipment to see if any areas had been compromised by the reduction of thickness due to corrosion. Ultrasonic Thickness Measurement (UTM) is a method of performing non-destructive measurement (gauging) of the local thickness of a solid element (typically made of metal, if using ultrasound testing for industrial purposes) basing on the time taken by the ultrasound wave to return to the surface.
Yes, quite an extensive inspection was carried out, but it needed to be as in its current state stripped down (naked) externally and with the small tubes out, it was the best time to really check out her condition. Well the good news is we received the go ahead to proceed with the next stage, being the reinstallation of the tubes.


    Christmas and a bit of well earned time off - December and January
    Not only that but its bloody hot..!!!!!


        • Phase 2 - Reassembly - Now that the (visual) boiler inspection is complete, we have got to the point in which the disassembly stage is over and reassembly commences.


          In early February, one by one, the team got back together, the first job that was required was to measure the tubes so they could be cut to the correct length. There is an unwritten rule in the boilermaking trade and that is to "measure twice and cut once", well we stretched this a bit and measured about twenty times prior to the first cut. We did this a couple of ways, firstly we placed some tubes (about 8) into the boiler in various locations spread out from top to bottom, left to right and positioned them flush to the fire box tube plate, we then marked the tube where it protruded into the smokebox flush to the smoke box tube plate. We then removed the tubes and recorded the length to the markings. Secondly we measured the length of about the same quantity (about 8) of the tubes that had been removed from the boiler and recorded these measurements also. In the first instance, allowances had to be made for the additional material that was required to protrude past both tube plates", 1/4 of an inch for the firebox end and 3/4 of an inch for the smoke box end. The second instance only required the 1/4 of an inch for the firebox end. So after all this a cut length was verified and so the slow heavy task of cutting the tubes commenced. After the first day, 21/02/2015, around half of the 93 required tubes were cut to length. The remaining tubes were all cut the following Saturday.
          Tubes Cut To Length
          Following completion of cutting the tubes to length, the next task would be to anneal the ends of them.Wikipedia explains the Annealing process better than I could so this is what it had to say; Annealing in metallurgy and materials science, is a heat treatment that alters the physical and sometimes chemical properties of a material to increase its ductility and to make it more workable. It involves heating a material to above its glass transition temperature, maintaining a suitable temperature, and then cooling. Annealing can induce ductility, soften material, relieve internal stresses, refine the structure by making it homogeneous, and improve cold working properties.So the annealing process was carried out over the weekends of the 7th and 14th of February.To do this a small oven was assembled using the brick arch bricks from the S class as the walls and roof, a heating torch was then inserted from the top and hey presto a gas oven was made. Each tube was then heated up at both ends and then allowed to cool slowly. This was a slow labour intensive task, many a tired body was the end result from each of the days activities.
          S Class Brick Arch Oven
          Meanwhile back over at the S class, a temporary wooded floor was assembled where the grate was previously fitted. This will allow a safe platform to work off during the tube fitting process. Also a final washout to remove the remaining scale in the boiler prior to the new tubes being fitted.

          Thanks go to Greg, Alec, Josh, Kirk, Jaydan, Chad and Dom for their contributions to the above activities, without them there would be nothing to write about.

          1 comment:

          1. Oww my aching back ... it will be worth it, it will be worth it, it will be worth it!!!

            ReplyDelete