This is a welcome contribution to the literature on Italian earthquake early warning.   To give passengers more confidence in the trigger criteria,  the authors may consider simulating the past significant historical earthquakes.  For each event, a conservative estimate may be made on the ground motions along the train route.  The authors should address the following question.  Are there any historical earthquakes which might have caused potentially dangerous shaking along the route - and which would not have triggered an alarm?  

Comments on the manuscript with title: “The first Earthquake Early Warning System for the high-speed railway in Italy: enhancing rapidness and operational efficiency during seismic events” by Simona Colombelli, Aldo Zollo, Francesco Carotenuto, Alessandro Caruso, Luca Elia, Gaetano Festa, Sergio Gammaldi, Antonio Giovanni Iaccarino, Giovanni Iannaccone, Alberto Mauro, Matteo Picozzi, Giulia Polimanti, Rosario Riccio, Stefania Tarantino, Francesco Cirillo, Andrea Vecchi and Franco Iacobini.

The document presents the first end-to-end Earthquake Early Warning System (EEWS) operating along the high-speed railway between Naples and Rome in Italy. It integrates seismic monitoring, signal processing, and railway-specific protocols to enhance the management of railway operation in case of earthquakes in a seismically active region. The EEWS takes advantage of an accelerometric network, predicting PGA in real-time, and of a decision-making module that dynamically updates alerts like train deceleration or halting. An important result is that the system targets specific segments, unlike traditional approaches that shut down entire lines, to minimize unnecessary disruptions. The submitted paper is of significant importance as the procedure can potentially be used worldwide to integrate seismic management into high-speed rail operations.

This manuscript is well-written with attention to the utilization of the English language. The research question and the intentions of the authors are clearly mentioned from the beginning.

In addition, even though the use of the English language is of good quality, several recommendations have been made through the manuscript.

The manuscript can be accepted after minor revisions.

All questions and suggestions for the main manuscript can be found as Sticky Notes through the edited pdf file, called “egusphere-2025-2668_Reviewer_1”.

Some of the main comments are:

1. Lines 52-53: “This is possible through the rapid detection of the early radiated signals from an ongoing earthquake”

This phrase is general and confusing. The rapid detection refers to the P-waves, which are generated simultaneously with the destructive S-waves. “Early radiated signals” are both P- and S-waves. Please rephrase.

2. Figure 1, caption: “the most relevant events”

What do you mean by “the most relevant events”? Are there more M≥5 earthquakes that have been reported/recorded in this area and are not shown in the map? And if yes, why? Please clarify.

3. Line 110: “Each station is equipped with a 3-component accelerometer”

Please provide some details regarding the accelerometers. E.g., are they broadband?

4. Lines 146-147: “When, at a given station, a potential P-wave pick originated by an earthquake is detected, its initial peak acceleration (Pa), velocity (Pv) and displacement (Pd) amplitudes are measured”

Pa, Pv and Pd cannot be measured. They are calculated. The phrase has to be corrected. In addition, it has to be mentioned that the calculation of Pa, Pv and Pd is described in Appendix B.

5.Line 190: “as long as the earthquake magnitude is updated and provided as output”

Please briefly describe how the earthquake magnitude is calculated.

6. Line 302: “This parameter is defined as the mean value of TFD for each specific configuration”

What is “TFD”? Please provide the full name. This must happen every time you use an abbreviation for the first time (and not when you re-use it).

7. Figure 5: It must be shown in Figures 5b and 5c that the “Length of the Alerted Segment of the Railway” and “L”, respectively, are in km.

8. Line 539” “corresponds to an Intensity (IMCS) equal to III”

What is IMCS? Please clarify.

Questions and suggestions regarding the “Supplementary Materials” can be found as Sticky Notes through the edited pdf file, called “933633c3-bf99-46e6-80c2-f3cf87ad5f49_Reviewer_1”.

Supplementary Material

1. Supplementary Text S1, Page 2: “surveys were conducted at each PT”

What is “PT”? Please provide the full name. This must happen every time you use an abbreviation for the first time.

2. Fig. S6. In the caption it is mentioned “In both panels, the size of the stars is proportional to the event magnitude”. This cannot be distinguished. All stars look the same. In addition, no magnitude range is either shown or mentioned. In both maps: A. Change the symbol of the epicenters to circles, so that the magnitude difference can be distinguished, B. Add a legend with the magnitudes and the respective symbols (sizes) on the map.