What is that loud noise?

Last week the top of the tender was finally put in place for rivetting.  We are preserving the original tender lid and coal boards, and marrying them to the new cistern bottom and sides.  It took a bit longer than anticipated, to get them matched up.  Then bolts were applied to the approximately 500 rivets holes, to hold it into position.  During the rivetting process, one worker climbs into the cistern (with a spotter and negative air-flow machine).  Then the bolts are removed in a coordinated pattern (to disperse the stress equally as the rivets are applied), and the worker in the tank watches in-the-blind as the red rivets to poke through, and applies the rivet snap with the pnuematic hammer.  Kind of like an industrial version of “Whack-a-Mole”  This work is being done in the roundhouse, you can’t miss it when its happening, it is loud!  Come by and hear it for yourself.  Hearing protection is strongly suggested. . .
DJ and Rob wiggle the coal board into place for rivetting.

DJ and Rob wiggle the coal board into place for rivetting.

Coal board is held on with bolts until rivets can be applied.

Coal board is held on with bolts until rivets can be applied.

The crew waits for the next batch of rivets to heat.

The crew waits for the next batch of rivets to heat.

The top of the tender is preserved from the original tender.  Here the old rivets can be seen alongside the new.

The top is preserved from the original tender. Here the old rivets can be seen alongside the new.

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Tender Update

This week, several coats of a high-tech epoxy-like paint (Ceramicoat) were applied to the interior of the water cistern, to prolong the life of the tank.  The exterior was also treated with a primer.  On Monday, the lid will be set in place, and then rivetting is planned for all day Tuesday, Wednesday and Thursday.  Visitors on the behind the scenes tour may be able to observe some of the final 400 rivets as they are applied, depending on the schedule.  It will be loud in the neighborhood!
The new tender sporting a new coat of primer.

The new tender sporting a new coat of primer.

Interior of tender, with first coat of the "ceramicoat" lining applied.

Interior of tender, with first coat of the "ceramicoat" lining applied.

Damage to old tender, caused by years of corrosion.

More Rivetting

To explain it in the most basic way-  rivetting is the old way of connecting two pieces of metal together.  Usually, holes are punched in both pieces of metal, and a red-hot steel pin with a head on top, is inserted in the holes.  Then two workers, each armed with pneumatic rivetting guns, fitted with hardened steel cups at the ends, push against the two sides of the rivet.  One worker is stabilizing the pre-formed head, while the other is forming the closing head on the other side. 

These days, a much better product is achieved by welding the metal together.  The resulting seam takes less work, is stronger, requires fewer workers and corrodes more slowly.  It also has a completely different finished look.

To achieve the best of both worlds, we are welding hidden seams on the new tender, and rivetting the exposed seams. 

Phil lines up the rivets in the forge to heat them.

Phil lines up the rivets in the forge to heat them.

Shop workers waiting for the rivets to heat to start rivetting.  
Shop workers waiting for the rivets to heat to start rivetting.
Red-hot rivets visible through the porthole of the forge.
Red-hot rivets visible through the porthole of the forge.
Phil runs the red-hot rivet to the tender, and inserts it quickly into the hole. James and DJ stand by, waiting to start.
Phil runs the red-hot rivet to the tender, and inserts it quickly into the hole. James and DJ stand by, waiting to start.
James and DJ put some weight into it, and complete the rivet.  Its loud!
James and DJ put some weight into it, and complete the rivet. This part is loud!
The finished rivet!  (The bolts on either side hold the unrivetted work in place).

The finished rivet! (The bolts on either side hold the unrivetted work in place).

Just 3,182 more to go!

Rivetting

Side of the tender cistern, example of a rivetted seam, and patch.

Side of the tender cistern, example of a rivetted seam, and patch.

Erik Young displays newly machined snap (l), and original snap from collection used as a model (r).

Erik Young displays newly machined snap (l), and original snap from collection used as a model (r).

 

Newly machined rivet snap showing cup at end used to mold the top of the hot rivet.

Newly machined rivet snap showing cup at end used to mold the top of the hot rivet.

Rivetting, as a method of connecting two pieces of metal, was once the method of choice in all forms of steel engineering.  Older buildings, ships, boilers, trains, bridges, were all built by use of rivets.

Rivetting is becoming a lost art.  Since the 1920s, it has been replaced by welded seams in most cases.  Welding creates a superior connection for several reasons.  While rivets hold the seams together, welding actually connects the two pieces of metal, with a continuous seam, which results in superior strength, and less corrosion. 

For the tender cistern on the Sierra #3, the decision was made to combine these two methods.  The visible areas(on the tops and sides) will utilize rivetted seams.  The hidden seams on the bottom will be welded.

Our machinist, Bob West, has machined new rivet snaps (the cups used to form the closing rivet heads), using original artifacts as a model.  We’ll be using these daily as we install over 3,100 rivets over the next month or so.