For many years prior to flashing color train order signals located on the position light mast, train crews were notified of train orders to be picked up by a system of metal order boards and colored globe lanterns.

Each block station had a bracket lagged into the frame of the tower and/or depot building/block office.  Into this bracket would be inserted a yellow train order metal board which was painted yellow on the side facing the train for which orders were to be picked up and black with a white stripe on the other side, signifying for trains approaching in that direction that the order board was not set out for them.

In earlier years (prior to 1927) a red board was used to indicate form 31 orders were to be picked up and, as they needed to be signed for by the conductor and engineer, they had to be distinctly different in aspect.  The last year of form 31 orders was 1926.  After that, only yellow boards were in use for form 19 orders.

The order flag or order board was used in daylight applications and at night, the board was hung with a lantern with matching globe (yellow for form 19 orders and red for form 31 orders).

This image shows a yellow train order board with lantern hung out at PD tower in 1971.  As it was a very gray, dreary, icy, wintry day, the board AND the lantern were hung to further catch the attention of the engineer / conductor of the approaching westbound train and notify them that they had orders to pick up.

The days of kerosene lanterns had long passed, so the train order lanterns were wired for use with a yellow electric light bulb. (Dave Keller photo, archive and data)

Form 31 order red flag and lantern

Form 19 order yellow flag and lantern

1925 PRR Book of Rules in use on the LIRR.  A handwritten note states that the red flag and lantern were discontinued by general order, effective September 19, 1939.  The last use of Form 31 orders was in 1926 and thus red was discontinued.  It appears that it took 13 years for the railroad to scratch this signal indication from their rule books.

According to the book of rules, the yellow order board was "v"ed out at the bottom, while the red order board was square; most probably to catch the eye and not have any confusion over flags. Archive/Research: Dave Keller 

The first initial installation of semaphore signaling, I find, is from an 1880 ETT description of Bedford Junction, 
opened in 1879. Research: Art Huneke  

First use of position light signal in lieu of semaphore signal on Long Island was on eastbound Joint track #2, New York Connecting Railroad track and was located on signal bridge 1,620’ east of “H” Interlocking station. General Order: NY, NH & HRR G.O. #3 Long Island RR G.O. #108-5 Pennsylvania RR G.O. #706 (Zone A – N.Y. Division) Eff: 6/25/28

First use of position light signals in lieu of semaphore signals ON A LIRR branch was at automatic block signal R143 on track 2 east of Hammel Rock. Beach branch) G.O. #109-11. Eff:5/15/29 in ETT #109,Eff: 10/17/28
Research: Dave Keller

The only aspects displayed at the low home eastward from the North Track/North Siding were stop signal and restricting.

Rule 290 is NOT a train order indication, it is a "Restricting" signal. The position light signal formerly south of the main track and adjacent to the former tower could display indications to proceed either eastward on the main, or onto a diverging route into the yard east of South Ocean Avenue, in addition to a "Train Order" indication. The dwarf (low home) signal that was formerly south of the North Siding controlled moves eastward from that track into the aforementioned yard, for what usually was a (and still is) a reverse move onto the main to go west from the station. Westward, there was a cantilever signal bridge that had a position light home signal that protected the yard moves. 

Dwarf "low home" signal aspect STOP

The LIRR Rules of the Operating Dept. are based on the "Standard Code of Operating Rules". We still have superiority between trains, Train Orders, Clearance Cards, etc...probably one of the last. Certainly, the largest remaining example of how a railroad operates on the Standard Code 2006.

RULE 290: RESTRICTED signal indication means to proceed at Restricted Speed prepared to stop short of train, obstruction or switch not properly lined and looking out for broken rail, not exceeding 15 MPH. Positions on the lower head would only be approached at slow speeds, therefore the PRR decided that crews had ample time to sight the black unbacked positions. 

With the introduction of Approach Slow in the late 1940's and Medium Approach in 1955 and 1956, there were lower arm aspects that would be approached at higher speeds.  I suspect this was the driving force behind full backgrounds for the lower arm.  I have no specific references, but it does seem that those full backgrounds seemed to become much more common starting in the later 1950's.  Info: Dave Morrison

RULE: 294 TRAIN ORDER signal means to pick up orders when flashing red. 

There were 2 types of train orders:  Form 19, which could be grabbed on the fly, and Form 31, which had to be signed for in person by the conductor and engineer. The flashing red light is an indication that the tower operator has a 31 for the crew to sign for.  In earlier times, a red lantern would be displayed.  If it were a 19, the operator would have a yellow lantern displayed, and that would signal the engineer and conductor to prepare to grab orders on the fly from the op's hoop or V-stick. Info: Art Single  

If PD had orders to give to a train, the operator would turn on the red flashing order light (Rule #294) and set the signals to stop until the train acknowledged PD's radio or called on the radio on why the stop board at the entrance into PD's interlocking/yard/station (the Distant [Approach] signal was at caution), after understanding there are orders to be pick up, the signal is cleared to show Approach as the train entered the station to get the orders.

Potter Ave Crossing view W 5/1943

PD had two MBS (Manual Block Signal) signals at the limits of PD, the east showed the block to BLS BO (Bellport), the west showed the block to Y Block station.

Card used in replacement of block signals in dark/manual block territory.
Collection: Paul Strubeck

PD controlled all the Block Limit Stations, BO, MO, PT, SK, WH, ND, SN, BH, AG, and MY (Montauk) until everything was transferred to Babylon, PD would issue "K" cards to allow passage by those BLS's without stopping, but reporting clear of the block station by radio to PD.

LIRR Training Dept. track maps dated 01/2000, "Y" and MS were controlled by PD. LIRR Training Dept. 
track maps dated 10/2010, "Y", PD, JJD (MS) and SK (Speonk) were remoted to Babylon. Also. all the 
remaining Block Limit Stations, WH, ND, SN, BH, AG, and MY(Montauk) are controlled by Babylon. (per the 10/2010 track maps)

K-card issued on PRR forms at PD tower back in 1941 by block operator Hotcaveg for westbound Montauk train #7.  This card shows all the block office call letters from Montauk (MY) westbound to Bellport (BO).  It also notes that the locomotive is PRR K2s #1458 with engineer Amott and conductor Dan Whaley.  I personally knew Dan Whaley.  He was about 85 at the time (1969) and was blind but rode the Scoot to and from Babylon daily using his lifetime pass, so he could kill time and shoot the breeze with the train crew.  AMOTT is the name of the CTC cabin at the end of double track on the Port Jeff branch just east of Syosset and from whence that name came. AMOTT CTC cabin at the end of double track on the Port Jeff branch just east of Syosset was named after several members of the AMOTT family who worked on the LIRR.   Archive/Info: Dave Keller

This order was copied on October 24, 1929 at "PD" tower in Patchogue. 
There will be flimsies as well as carbon-coated-back forms in use during these years. This order was copied by block operator Rees and again, the initials of F. R. G. represented Super Felix R. Gerard.  Train #63 to whose crew the order was addressed, was the Patchogue-Babylon "Scoot".  The block station identified in the order as "Y" was the block office cabin at the end of double track east of the station in Sayville.  

It must've been some Labor Day weekend out east back in 1909 as this Form 31 train order indicates.  Four locomotives are going to be pulling FOUR sections of train #23 west to handle all the crowds.  As the Form 31 train order had to be signed for by both engineer and conductor, you'll notice that there are two sets of signatures on this specific order, conductor Phillips and engineer Murray of the 1st section of train #23 and conductor Ohn and engineer Sylvester Doxsey of the 2nd section of train #23.  Both were countersigned by block operator Schmidt.  No idea why the C and E of the other two sections did not sign, but they will definitely have to sign once they arrive at "PG" ( Patchogue block office as "PD" tower [1912] was not yet constructed). Info: Dave Keller

PD Tower 01/1972
Photo: Dave Keller

PD Tower Photo: Chris Allen

LIRR F7A #622 PD Tower 
winter c.1992-93

04/2006: 3 Color lights were installed at PD-JJD-SK 

8/14/2006  Photo: Nick Kudreyko

ex-PD Tower - View E 3/16/2019 
Photo/Archive: Dave Morrison

Underwood Coal Co. 10/1943 view W of  River Ave.  Photo: (Weber-Keller)

The signal on the right is the Manual Block Signal to "Y" Block station, and the 2 headed signal on the left is the west limit of PD. Back then MS (aka JJD) was controlled by PD. JJD were the initials of a past LIRR President (2003-2006), James J. Dermody, that controlled the siding at MS was named for him in the '90's

EAST of PD

RDC's RPO trailer westbound approaching PD Tower,
Patchogue 1956 (Huneke-Keller)

ROW Track Gang - Patchogue View E from PD Tower
10/1971 Photo/Archive: Dave Keller

Ocean Ave view W 4/29/2006

The reason for the position light signal on the left side of the track is because there is no room for it on the right side of the track. 

West of Ocean Ave view W 9/09/2006
 

Signal W1 east of Ocean Ave view W 4/27/2022
Photo/Archive: Joe Vila

PD-2 R.C. Interlocking Cabin - South Ocean Ave.
View E 5/06/2006 Archive: Dave Keller

3 lights: If routed to the Fence track at PD, top red, middle red, bottom yellow(restricting)10 mph thru the crossover and the switch into the fence track.
If routed thru the siding at PD then back to main track top red, middle yellow, bottom red (med approach) 10 mph thru crossover expecting a stop signal next.

PD Tower Sign, Photo: Joe Gregory 2005