OK, I have been wondering this for a long time. Los Gatos Vasona Park ex-Venice Railroad #2 was rebuilt in the 1990s. Before, it had a curved eccentric rod (see photo). After, it had a straight eccentric rod. I always thought the curved rod gave it some elegant character. Why the change?

Could have been bent in place of forging it shorter when the valves were set.

Hi
Changing the length of the eccentric rod, the lead of the valve is increased at one end and decreased at the other end. This all depends on which end the change is made.
The valve gear will still have full valve travel, remains the same, the only change that would be different, will the distance the valve travels inside the port of the valve, the steam chest.
So the bend eccentric rod was giving the engine, either more travel, either in full forward gear, and it was also giving the valve either a shorter, cutoff, in the valve, or a longer cutoff.in the valve.
So it was possible when the locomotive, built, there was no way, to adjust the valve via the reverse lever.
The engine either ran in full forward gear or full reverse gear, there was no cut off on the reverse quartet.
So the bend eccentric rod was providing cutoff to the valve.

I have never seen a bent rod on a locomotive. "Elegant character?" I'm not seeing it. It looks damaged to me.

The bent eccentric rods was applied in her later service years at Venice in the mid 1920s. I used the word "applied" since the same modification was made to the Venice Railway #1, an identical 18" gauge 2-6-2.

#2 continued operating with the bent eccentrics until the 1980s when new eccentrics were made. The #1's bent eccentrics were replaced by the 1950s.

Since the modification was made to both locomotives, an assumption can be made that some sort of operational improvement was sought by the shop crews in Venice.


Ken Middlebrook
Billy Jones Wildcat engineer since 1981.

As small as they are, why didn't they just make new sorter eccentric rods?

I'm not sure I'm convinced that it was an operational improvement. If it was applied to two locomotives, and continued throughout the years, I'd have to assume it was more of a "ooh, that looks nice" appeal.

The rods could have been re-made with shorter dimensions, which is why I think it was a cosmetic modification. I think it'd be a bigger challenge to bend the eccentric rods along the cross section while holding the tolerances needed for correct valve events, than it would be to redesign the eccentric rods with shorter numbers.

Does anyone else agree with me that it looked elegant?

Nope. Looks like an oops to me.