Attachment 8- GPO Printing Press Location Vibration Study (2).pdf

August 21, 2023

Luis Gallegos

GPO

732 North Capitol Street NW Washington, DC 20401

Re: GPO Printing Press Location Viability Study C&A #244910.0006

Dear Luis, On January 23, 2024, we visited the GPO to measure vibration levels at the proposed location for the new 8 Color Koenig & Bauer printing press. Included below are the results of our survey and commentary regarding next steps.

1.0 Measurement Procedure

In order to capture the expected levels of typical vibration present at the future location for the new press, an accelerometer was placed at the location shown in Figure 1 below, along with the estimated footprint of the new press.

Figure 1: Test and Press Location

Measurements were performed at this location under the following conditions, with various pieces of equipment turned on and off. Please note that if an individual piece of equipment is identified, no other printing press equipment was in operation during that test.

GPO Printing Press Location Viability Study Cerami Project No. 244910.0006 Submitted 8/21/2023

• 6 Color Press o Closest equipment to the proposed location

• ZMR Press o Located in the Northwest corner of the floorplan

• 4-Color Press o Located in the approximate middle of the floorplan

• Forklift Passes o Along the corridor immediately adjacent to the proposed location

• All Equipment and Forklift Passes o All presses identified above in operation in addition to forklift passes

• Heel Drops o Controlled impulse tests immediately adjacent to the proposed location

Results from these tests are included in the figures below, with acceleration data included in Figure 2 and the associated displacement in Figure 3.

Figure 2: Acceleration Results (m/s^2)

GPO Printing Press Location Viability Study Cerami Project No. 244910.0006 Submitted 8/21/2023

Figure 3: Displacement Results (m/s)

2.0 Analysis

From the acceleration test results, the most significant level of vibration generation came as a result of the forklift passes, the operation of the nearby 6-color press, and the test performed with all equipment in operation; however, the displacement results indicate that the forklift passes appear to be responsible for a majority of the vibration levels received at the measurement location. The spectral content of the forklift passes and the “all equipment on” tests are very similar, especially at 8 Hz, 16 Hz, and 1600 Hz, peaking at 0.009mm at 8 Hz.

These values most likely coincide with the natural response of the slab to impulses. The peak seen in the acceleration data at 1600 Hz from the operation of the 6-color press is the result of the operation speed of that piece of equipment exciting the slab at that octave; however, the high levels of acceleration shown at this frequency do not translate to high levels of displacement as shown in Figure 3.

Per the provided K&B installation plan, the base operation frequency for this printing press is 5.56 Hz, where the highest amplitude occurs and decreases until the 7th harmonic. For ease of reference the following are the 2nd through 7th harmonic frequencies of the 5.56 Hz base operation frequency.

Table 1: K&B Press Operation Frequencies

Harmonic Frequency (Hz)

Base Operation Frequency 5.56

2nd Harmonic 11.12

3rd Harmonic 16.68

4th Harmonic 22.24

5th Harmonic 27.8

6th Harmonic 33.36

7th Harmonic 38.92

If we view the displacement chart (Figure 3) with this spectral data in mind, we see that the peak at 16 Hz coincides with the 3rd harmonic of the base operation frequency:

Figure 4: Displacement Results w/ Press Harmonic Data

Base Op.

Frequency

2nd Harmonic

3rd Harmonic

We note that in the hallway where the forklift passes occurred, there was a change in flooring type immediately adjacent to the press location:

Figure 5: Hallway Flooring Change

This flooring change causes a feelable and measurable impulse to the slab when the forklift travelled over this bump. Based on the results summarized above, we believe that the operation of forklifts within this hallway will be the biggest contributor to vibration levels at this new press location, especially at 16 Hz, which coincides with the third harmonic of the base operation frequency of the new press.

Without further information from the manufacturer, it will be difficult to determine whether this level of vibration transmission will be detrimental to the operation of this machinery.

Regards, James Meade Associate