ALL THINGS BIG BOY

Discussion of steam locomotives from all manufacturers and railroads

Moderators: Typewriters, slide rules

Re: UP Class 4-8-8-4 "Big Boy" Maximum Cut-Off

Postby joeburgard540 » Wed Oct 13, 2010 6:59 pm

Thanks Will, nice to know my figures correspond. Just curious as to what source you got that from? Also what is RME?

I drew some Zeuner diagrams for full gear (hand drawn and CAD) based off the info on UP drawing 585 CA 30809, the valve diagram:
Valve Diameter - 12"
Valve Travel - 7"
Steam Lap - 1.375"
Lead - 0.25"
Exhaust Clearance - 0.125"

Results:
Lead Angle - 27.7 degrees
Cutoff - 81.6%
Release - 93.4%
Compression - 4.86%
Admission - 0.15%

As a side note, UP drawing 683 CA 31236 dated 5 August 1944 gives the Power Reverse Gear as the 12" ALCO Type "M". This is for locos 4-8-8-4 #4000-4024 and 4-6-6-4 #3930-3999.

Cheers - Joe
"If a nation expects to be ignorant and free, it expects what never was and never will be." Thomas Jefferson
User avatar
joeburgard540
 
Posts: 7
Joined: Tue Oct 12, 2010 6:51 pm
Location: Texas

Re: UP Class 4-8-8-4 "Big Boy" Maximum Cut-Off

Postby Typewriters » Thu Oct 14, 2010 8:03 pm

That's all from my brother's library, specifically the Gregg reprints of specific articles from RME or Railway Mechanical Engineer, which for those unfamiliar was the real biblical trade paper as far as new steam locomotive construction was concerned. I don't know why your drawings list "Type M" and RME states "Special Type H" unless they're one and the same with two different (ie earlier and later) designations.

-Will Davis
Moderator- Steam Locomotives forum

http://www.railroadlocomotives.blogspot.com
User avatar
Typewriters
 
Posts: 272
Joined: Fri Mar 12, 2004 8:29 pm

Re: UP Big Boy Steam Turret: Vents?

Postby joeburgard540 » Mon Jan 17, 2011 12:49 pm

My bad...I misread your question and to clarify. The two steam plumes on the turret (just ahead of the cab) are the exhuast for the cold water pump and the Nalco Automatic Blowdown. The third plume of steam nearly always seen is from the Pyle National turbo-generator (ahead and on the left or fireman's side of the turret).

Joe
"If a nation expects to be ignorant and free, it expects what never was and never will be." Thomas Jefferson
User avatar
joeburgard540
 
Posts: 7
Joined: Tue Oct 12, 2010 6:51 pm
Location: Texas

Big Boy

Postby tv737 » Mon Jan 27, 2014 8:33 am

tv737
 
Posts: 11
Joined: Sat Sep 25, 2010 6:13 am

ALL THINGS BIG BOY

Postby John_Perkowski » Mon Nov 21, 2016 3:42 pm

Admin Note:
This thread applies to anything related to a Union Pacific F-E-E-F or 4-8-8-4 articulated locomotive.
~John Perkowski: Moderator: General Discussion: Locomotives, Rolling Stock, and Equipment
Assistant Administrator: Railroad.net/forums
Please don't feed the spammers! If you see spam, please notify a Moderator
User avatar
John_Perkowski
 
Posts: 4758
Joined: Wed Mar 17, 2004 5:12 pm
Location: Off the Q main near Parkville MO

Re: ALL THINGS BIG BOY

Postby dan the ca railfan » Wed Oct 10, 2018 1:06 pm

they are restoring a big boy locomotive for the 150th anniversary of the transcontinental railroad. yep for the first time since the 1950s i believe a big boy locomotive will be steaming again.

https://www.atlasobscura.com/articles/w ... locomotive
dan the ca railfan
 
Posts: 13
Joined: Thu Sep 20, 2018 3:54 pm

Re: ALL THINGS BIG BOY

Postby John_Perkowski » Fri Mar 29, 2019 9:28 pm

As an update, they’ve done the hydrostatic test and the early live steam tests, and they are filling 3985s tender.
~John Perkowski: Moderator: General Discussion: Locomotives, Rolling Stock, and Equipment
Assistant Administrator: Railroad.net/forums
Please don't feed the spammers! If you see spam, please notify a Moderator
User avatar
John_Perkowski
 
Posts: 4758
Joined: Wed Mar 17, 2004 5:12 pm
Location: Off the Q main near Parkville MO

Re: ALL THINGS BIG BOY

Postby John_Perkowski » Wed Apr 10, 2019 12:26 pm

As an update...

Yesterday, the Steam Shop in Cheyenne lit off 4014s oil burners.

A Big Boy is under steam again.
~John Perkowski: Moderator: General Discussion: Locomotives, Rolling Stock, and Equipment
Assistant Administrator: Railroad.net/forums
Please don't feed the spammers! If you see spam, please notify a Moderator
User avatar
John_Perkowski
 
Posts: 4758
Joined: Wed Mar 17, 2004 5:12 pm
Location: Off the Q main near Parkville MO

Previous

Return to Steam Locomotives

Who is online

Users browsing this forum: No registered users and 2 guests